How to Stop Emails Going in Spam 2025 – Ultimate Email Marketing Guide

Introduction

Ever sent out a carefully crafted marketing email only to find it languishing in the dreaded spam folder? If so, you’re not alone.

For many small and medium-sized businesses in the UK – from SaaS startups to e-commerce shops – unwanted detours to the spam folder are a common frustration. You might be asking, “why are my emails going to spam if they’re not actually spam?” The truth is that modern email filtering is complex, and even legitimate emails can get caught in the net. In fact, studies show the average email deliverability rate is around 83%, meaning roughly 1 in 6 marketing emails never reaches the inbox. That’s a lot of potential customers not seeing your messages!

The key question is how to stop emails going to spam. There’s no single quick fix or magic wand to solve this overnight – it’s a blend of technical tweaks and smart strategy. Think of improving email deliverability like getting healthy: you can’t rely on a one-time pill. Instead, you need a balanced approach (a bit of technology, a bit of content strategy, and a lot of consistency) to nurse your emails back to the inbox. The good news? By the end of this guide, you’ll understand the main factors that influence spam filtering and have a clear roadmap to improve your email inbox placement over time. We’ll also highlight handy tools (like Google Postmaster Tools and MX Toolbox) and resources (including a free Inbox Scorecard call from Digistrat) to help you along the way.

So, grab a cuppa and let’s dive in. Stopping your emails from going to spam isn’t an overnight task, but with the right steps, you can greatly increase your chances of reaching your customers’ inboxes. Let’s explore the why’s and how’s in a conversational, no-nonsense way.

Understanding the Spam Folder Dilemma

Before jumping into solutions, it’s important to understand what’s happening when an email goes to spam. Email providers like Gmail, Outlook, and Yahoo use spam filters to protect users from unwanted or dangerous messages. These filters look at a huge range of factors – from technical details in the email’s header to the content of the message and how recipients interact with it. Every incoming email earns a sort of “spam score”. If that score is too high (meaning the email looks suspicious or low-quality), the provider will route it to the junk/spam folder instead of the inbox.

For businesses, the spam folder is a black hole where your marketing efforts can vanish without a trace. You might have great deals or important updates to share, but if they’re not seen, they can’t have an impact. This is often referred to as email deliverability – the success rate at which your emails actually reach the inbox rather than getting filtered out. With nearly half of all emails worldwide considered spam by volume, email providers are understandably strict about filtering. The challenge is that sometimes legitimate emails from well-meaning companies get caught in the crossfire.

In short, ending up in spam is not usually personal – it’s algorithms doing their best to sort millions of messages. But if you consistently find your emails sidelined, it’s a sign that something about your sending habits or setup is red-flagging those filters. Let’s unpack the common reasons why your emails might be going to spam, so we know what to fix.

Why Are My Emails Going to Spam?

It’s the million-pound question: “Why are my emails going to spam?” There’s rarely a single answer. Typically, it comes down to a combination of issues that together make your emails look suspicious to spam filters. Here are the most common culprits:

1. Lack of Proper Authentication

If email servers can’t verify that an email claiming to be from your company actually came from you, they get very nervous. Email authentication is like the passport or ID for your emails – it proves you are who you say you are. The main authentication protocols are SPF, DKIM, and DMARC (more on these later). If these aren’t set up correctly, your emails might fail checks and be treated as potentially fraudulent or spoofed. Think of it this way: an email without proper authentication is like a letter without a valid return address or stamp. Many mail servers will refuse to deliver it to the inbox because they can’t be sure it’s legit. So if you haven’t configured things like SPF (Sender Policy Framework) or DKIM (DomainKeys Identified Mail) for your sending domain, that’s a big reason emails go to spam.

2. Poor Sender Reputation

Every domain or IP address that sends email has a sender reputation – basically a score or history that inbox providers track. If your organisation has a poor reputation, your emails are more likely to be filtered out. What harms your reputation? Things like a high rate of recipients marking your emails as spam, frequent bounces (sending to invalid addresses), or sending large volumes of email to people who don’t engage with it. It’s similar to a credit score: if you’ve “defaulted” by spamming people in the past (even unintentionally) or sending to many dead addresses, your score drops. ISPs (Internet Service Providers) remember that and will be cautious with your emails. A bad reputation can come from past mistakes like using purchased email lists, blasting out too many emails too quickly, or not removing contacts who never open your emails. All these signal to mailbox providers that your mail might not be wanted. In short, your sending domain and IP need to build trust over time, and if that trust is broken, emails end up in spam.

3. Spammy Content or Design

Sometimes, the content of your email itself waves the red flag. Spam filters scan what you’ve written and how you’ve designed your email. If your message contains a lot of “spam trigger” words or phrases (e.g. “FREE MONEY!!!” or “Work from home and earn $$$”), excessive use of ALL CAPS or too many exclamation marks, it can look suspicious. Likewise, misleading subject lines (like saying “Re: Important Update” when it’s not actually a reply) can trigger filters. Even the formatting matters – an email that is one giant image or has very little actual text might be seen as trying to hide something. Poor HTML code, broken links, or attaching unexpected files can also hurt. Essentially, if your email looks and reads like those sketchy spam emails we all hate, the filters will treat it accordingly. Even an honest email can accidentally resemble spam if you’re not careful about wording and design. So, content that’s overly salesy, shouts at the reader, or is full of flashy graphics but no substance could be a reason it’s landing in junk.

4. Low Engagement and Subscriber Issues

Email providers also pay attention to how recipients interact with your emails. If a lot of people don’t open your emails at all, or delete them without reading, that’s a negative signal. Even worse, if people frequently mark your messages as spam or junk, that’s a huge red flag for filters. Low engagement can mean your list includes many people who aren’t interested in your content anymore. Perhaps you haven’t pruned your list in years and it’s full of inactive addresses, or you onboarded a bunch of contacts who never really opted in enthusiastically. Additionally, if you send emails too often or in a manner that annoys recipients, they might start ignoring you or complaining. All of this feeds back into your sender reputation. Think of it like a restaurant: if regular customers stop coming or start leaving bad reviews (“complaints”), the place gets a bad rep in town. Similarly, low engagement tells ISPs that users don’t love these emails, so maybe they belong in spam.

5. Technical Misconfigurations

Beyond the big three (SPF, DKIM, DMARC) we mentioned, there are other technical setups that can trip you up. For instance, if your DNS records (like MX records for your domain) are not configured correctly, or if you’re sending from a new IP/domain that isn’t warmed up, issues can arise. Sometimes companies switch email service providers or marketing platforms and forget to update settings, resulting in emails failing checks. Broken unsubscribe links or missing headers that identify the mailing software can also look fishy. ISPs have lots of little technical rules, and while you don’t need to obsess over every tiny detail, a glaring misconfiguration can be an easy reason for a filter to divert your mail to spam. Always ensure the basics are in place: a valid From address, proper headers, a List-Unsubscribe header, and so on. Ignoring these is like forgetting to bolt the wheels on a car – it might still roll for a bit, but something will go wrong eventually.

Those are the major reasons emails end up in spam. Often, it’s not just one thing but a combination – for example, a slightly damaged sender reputation plus a couple of spammy phrases in your content plus an out-of-date email list. Together, they push the filter’s judgment over the line. Now that we know the why, let’s look at how to stop emails from going to spam. Spoiler: as we said, there’s no single trick, but a series of best practices you can implement. It’s time to roll up our sleeves and start fixing the problem from multiple angles.

No Quick Fix: Take a Holistic Approach

By now, you’ve likely realised there’s no single switch to flip to magically fix deliverability. If someone promises a one-click solution to keep emails out of spam, be sceptical. The reality is that improving inbox placement is a bit like improving your health – you need to work on different areas consistently. Just as a healthy lifestyle includes a mix of good diet, exercise, and sleep, good email deliverability comes from a mix of proper technical setup, good sender practices, and valuable content strategy.

It’s worth emphasising: there is no magic wand or cheat code for beating spam filters. You have to address the issue holistically. The upside is that each small improvement you make (better authentication here, a cleaner list there) adds up to a big difference in where your emails land. Yes, it requires some effort and patience, but this also means your competitors who look for quick hacks will keep struggling, while you steadily improve.

Think of the process as building your sender reputation and trust step by step. We’re going to tackle this from all sides – technical fixes, content tweaks, list management, and ongoing monitoring. Together, these steps form a robust strategy to stop your emails going to spam as much as possible. Let’s break down the key actions you should take.

Authenticate Your Emails with SPF, DKIM, and DMARC

One of the first and most important steps is setting up proper email authentication. This is the foundation of proving to the world (and to Gmail, Outlook, etc.) that you are a trustworthy sender. The big three protocols to implement are SPF, DKIM, and DMARC:

• SPF (Sender Policy Framework): SPF is like an approved senders list for your domain. You add an SPF record in your domain’s DNS settings, which lists which mail servers are allowed to send emails on behalf of your domain. When an email goes out claiming to be from your domain, the receiving server checks your SPF record to see if the sender’s IP is on the list. If it is, great – you’re essentially saying “Yes, that sender is one of ours.” If not, the email might be treated as forged or suspect. Analogy: Think of SPF as the guest list at a club – if you’re not on the list, you might not get in. Make sure all the services you use (your CRM, email marketing platform, etc.) are included in your SPF record.

• DKIM (DomainKeys Identified Mail): DKIM works like a tamper-proof seal on your emails. It uses a pair of cryptographic keys: one private (kept by your sending server) and one public (published in your DNS). When you send an email, your mail server adds a special DKIM signature to the message header, which is generated using the private key. The receiving server can fetch your public key from DNS to verify that signature. If the signature checks out, it proves the email hasn’t been altered in transit and indeed comes from a domain that has the private key (presumably you). Analogy: It’s like signing a letter with a unique wax seal that recipients can verify against your known seal imprint. A valid DKIM tells spam filters that the content of the email is exactly as you sent it and not from an impersonator.

• DMARC (Domain-based Message Authentication, Reporting & Conformance): DMARC builds on SPF and DKIM. It’s a policy layer that tells receivers what to do if an email fails SPF/DKIM checks. With DMARC, you publish a DNS record that says, for example, “If an email from mydomain.com fails authentication, please reject it (or quarantine it in spam). And also send me a report about those failures.” DMARC helps you get visibility through aggregate reports, and it enforces that spoofed emails (which don’t pass SPF/DKIM) should be handled in a specific way. Analogy: DMARC is like an instruction to the mail sorter – “If the ID (SPF/DKIM) doesn’t match, don’t deliver the letter and let me know about it.” Implementing DMARC with a policy of at least monitoring (p=none with reports) is highly recommended. Over time you can move to stronger policies (quarantine or reject) once you’re sure all your legitimate mail streams are authenticated.

Setting these up might sound technical, but most of it is done by adding DNS records. Many email service providers and IT teams can guide you through it. There are even user-friendly tools like EasyDMARC that can help you generate DMARC records and view DMARC reports to understand who is sending email on your behalf. Proper email authentication not only boosts deliverability but also protects your brand from phishing or spoofing attempts.

Tip: After setting up SPF/DKIM/DMARC, use tools to verify your records. For example, MX Toolbox offers a free lookup to check your SPF record and DMARC configuration, and Google’s G Suite Toolbox has a dig feature to view DNS records. You want to ensure there are no typos or errors in those DNS entries. Once authentication is in place, you’ve built the trust framework that tells filters “I am who I claim to be.” This alone won’t guarantee inbox placement, but without it, you’ll have a hard time ever escaping the spam folder.

Maintain a Healthy Sender Reputation

As discussed, your sender reputation is basically your email “credit score.” Improving it is crucial to stop emails going to spam. How do you cultivate a good reputation? Here are several strategies:

• Warm Up New Domains or IPs: If you’re using a new sending domain or IP address (for instance, you’ve just switched to a new email marketing platform or set up a new subdomain for emails), don’t go zero-to-60 with your sending volume. ISPs treat unknown senders carefully. Gradually increase your sending volume over a few weeks so you can “earn” a good reputation. This is often called IP warming or domain warming. Start with your most engaged contacts first (those likely to open and click), so you gather positive engagement signals early on.

• Send Consistently: Consistency in sending volume and frequency helps build a stable reputation. If you send 500 emails one week, 50,000 the next, then go silent for a month and repeat, it looks erratic and can be a red flag. Aim for a predictable sending pattern that ISPs can get used to. For example, sending a newsletter every Tuesday at 10am, or maintaining a steady daily volume if you’re sending transactional emails.

• Monitor Your Complaint and Bounce Rates: Keep an eye on how many spam complaints you get (many email service providers show you this metric). A high complaint rate will tank your reputation quickly. Industry-wise, a spam complaint rate above about 0.1% (i.e., 1 complaint per 1,000 emails) is cause for concern. Similarly, monitor your bounce rate – if you’re sending to a lot of invalid addresses that bounce back, ISPs see you as a sender who doesn’t maintain their list (more on list hygiene in the next section). Use tools like Google Postmaster Tools to check your domain’s reputation as seen by Gmail; it will show if they classify your reputation as high, medium, low, or bad, based on factors like user complaints and spam trap hits.

• Avoid Public Blacklists: Spam filters often reference blacklists – lists of IPs or domains known to send spam. If your sending IP or domain appears on a major blacklist like Spamhaus, there’s a good chance your mail will be blocked or filtered. Use a tool like MX Toolbox (which offers a multi-blacklist check) or a dedicated blocklist checker to regularly see if you’re on any blacklists. If you find yourself listed, you’ll need to diagnose why (usually a spam trap hit or high complaints) and then follow the blacklist’s removal process. Keeping your nose clean with good practices will generally keep you off blacklists in the first place.

• Use a Reputable ESP (Email Service Provider): This might seem obvious, but using a well-established email sending service or SMTP provider can indirectly boost your reputation. Big providers (like SendGrid, Netcore Mailchimp, etc., or specialist UK-based ESPs) often have feedback loop arrangements with inbox providers, meaning they hear about complaints and can auto-suppress those recipients for you. They also manage their IP ranges’ reputations carefully. If you try to send bulk emails from your own server or from a cheaper service that doesn’t manage reputation, you might find yourself in a shared IP pool with bad actors. In short, partner with email providers known for good deliverability – it’s like using a reliable courier to ensure your letters get delivered safely.

Building a good reputation isn’t instantaneous – much like trust in real life, it accrues over time with consistent good behaviour. If you’ve had issues, don’t despair; you can rehabilitate a damaged reputation by changing your practices today. Senders can recover from being “flagged” by slowly demonstrating improvement (e.g., halting all bad practices, focusing only on engaged recipients, etc.). Some companies, like Digistrat (which we’ll mention later), even offer sender reputation repair services to help get you back on track. But a lot of it comes down to common sense: only send emails people want, and handle your sending infrastructure responsibly.

Clean Your Email List Regularly (List Hygiene)

Imagine trying to carry on a conversation with people who left the room – pointless, right? Sending emails to people who aren’t there (invalid addresses) or who aren’t interested anymore is not just unproductive, it actively harms your deliverability. List hygiene is the practice of keeping your mailing list clean and up-to-date. Here’s how to do it:

• Remove Inactive Subscribers: Over time, some people on your list will stop opening your emails. It happens – inboxes get cluttered or interests change. If someone hasn’t engaged with any of your emails in a long time (say 6-12 months), consider removing them or at least running a re-engagement campaign to confirm they still want to hear from you. Why? Because continuing to send to a lot of unresponsive recipients tells mailbox providers that your content might not be wanted. Low mailbox usage is actually cited as a top reason for poor inbox placement. Pruning inactive subscribers can boost your open rate and send a positive signal that “hey, people actually like these emails.”

• Eliminate Invalid Emails and Typos: Use double opt-in when possible (where users confirm their email address) or at least a verification at sign-up to avoid typos like [email protected]. If you do get bounces from invalid addresses, make sure those are suppressed and not retried over and over. Many ESPs automatically handle hard bounces by never sending to them again. If you manage your lists manually, you need to do this cleanup yourself. Sending repeatedly to bad addresses can land you on spam trap lists (some recycled old addresses turn into spam traps).

• Don’t Buy or Rent Email Lists: It can be tempting for a quick growth hack, but purchased lists are notoriously filled with uninterested recipients, old/stale contacts, or even spam traps (addresses that were never real or are used solely to catch spammers). Sending to such a list is almost guaranteed to get you high bounces and complaints – a deliverability disaster. Instead, grow your list organically through your website, content, and promotions where people willingly sign up. The quality will be much higher. Remember, permission is everything. One of the golden rules of email marketing (and indeed UK law via GDPR/PECR) is to only email people who gave clear consent.

• Segment and Target: This isn’t exactly cleaning, but while we’re on the topic – segmenting your list can improve engagement. If you send relevant content to the right people, they’re more likely to open and less likely to ignore or complain. For example, if you have some subscribers interested in SaaS product updates and others interested in industry news, segment those groups and tailor your emails accordingly. Higher engagement from interested audiences will make your overall sender metrics look better, helping you stay out of spam.

Performing regular list hygiene is like taking your car in for a service. It ensures everything is running smoothly and prevents bigger problems down the line. Yes, it can feel counter-intuitive to delete subscribers (you worked hard to get them!), but a smaller list of engaged readers is far more valuable than a huge list that mostly doesn’t care. Quality over quantity is the motto here for better deliverability.

Avoid Spammy Language and Design in Emails

Now let’s talk about the content of your emails – what you’re actually sending out. While modern spam filters have evolved beyond just simple keyword checks (they look at a lot of things), your email’s content still matters. You want to avoid looking like a spammer in what you say and how you say it. Here are some tips:

• Use a Natural, Professional Tone: Write your marketing emails somewhat like you’d speak to a customer in person. Personalise it (use their name if possible, etc.), be conversational but also clear. Avoid over-the-top claims (“ACT NOW OR YOU’LL MISS OUT FOREVER!!!”), too many promotional buzzwords, or anything that sounds like a scam. One or two exclamation marks won’t kill you, but multiple in a row, or shouting in ALL CAPS, definitely looks spammy. For instance, “Get your free offer now” might be okay in context, but “FREE MONEY” is a huge no-no. Think about phrases that might trigger skepticism – if it sounds like what you see in your own spam folder, rewrite it.

• Balanced Use of Images and Text: Having a nice-looking email with images is great, especially for e-commerce showcasing products. But don’t send an email that is just one big image with little or no text. Image-only emails are a known tactic spammers use to hide text from filters. Always include a good balance of text to explain the images or offer. Also, use alt text for images (helps accessibility and spam filters can read that too). A rule of thumb some senders use is a 60/40 or 70/30 ratio of text to image area.

• Proper Formatting and HTML Code: If you’re using an email template builder, you’re probably fine. But if you craft HTML emails manually or hire designers, ensure the code is clean. Broken HTML tags, extra unused code, or weird formatting can sometimes trigger filters. Keep your styling simple and mobile-responsive. Make sure your links are legitimate URLs (ideally pointing to reputable domains, e.g., your own site or known link trackers). If you link to a shady looking URL, that’s a problem. Also, avoid linking to known bad sites or including scripts. Basically, keep the email as a straightforward HTML/CSS document without funky stuff.

• Spam Checker Tools: Consider running your email content through a spam check tool before sending. Tools like Mail-Tester.com or the built-in spam checking feature in services like Mailtrap or Litmus can analyze your email and flag common spam triggers. They often give a score or list of things to improve (like “your message mentions ‘free’ 5 times” or “missing plaintext part” etc.). This can catch issues you might not notice yourself. It’s like proofreading your email for deliverability.

• Clear and Honest Subject Lines: Your subject line is the first thing both the recipient and spam filter see. Don’t try to deceive. Avoid using “Re:” or “Fwd:” in subject if it’s not actually a reply or forward – that trick is old and filters know it. Don’t promise something in the subject that the email doesn’t deliver. Not only will that annoy readers (leading to deletions or complaints), but some spam filters use AI to judge if the subject and body align in purpose. And again, no ALL CAPS or ☢emoji overload☢ in the subject. Aim for brief, relevant, and intriguing – but not clickbait – subject lines.

By keeping your content legitimate and reader-friendly, you’re not giving the spam filters obvious reasons to doubt you. Think of it as dressing your emails in business-casual attire: professional but personable. You want to come across as a trustworthy business, not a dodgy scammer from parts unknown. High-quality content also has the benefit of engaging your audience more, which, as we discussed, further improves your reputation. It’s a win-win.

Send Emails Your Subscribers Actually Want

This might sound like general marketing advice, but it’s deeply connected to deliverability: focus on providing value to your subscribers. If people genuinely look forward to your emails, guess what? They’ll open them, click them, and even interact positively (replying, forwarding to colleagues, etc.). All those signals tell mailbox providers that your emails are wanted, which helps keep you out of spam.

How do you ensure your emails are wanted? A few ideas:

• Relevant Content: We touched on segmentation earlier. Use what you know about your subscribers to send them content that makes sense. If you run a mobile app business and have both free users and paid subscribers on your list, consider separating your messaging. The paid folks might want advanced tips and feature updates; the free users might respond better to an offer to upgrade after seeing value. Tailoring content increases the chances of engagement. Many marketing platforms allow dynamic content or conditional blocks so you can send one campaign that shows different content to different segments.

• Frequency and Timing: Hitting the right email frequency is important. Too frequent and people feel spammed (ironically by a legitimate sender) – they tune out or mark as spam. Too infrequent and they might forget who you are and think “who is this?” when you do email (also a path to the spam button). There’s no one-size rule, but a good practice is to set expectations on sign-up (“We’ll send a monthly newsletter and occasional special offers”). If you then suddenly start emailing daily, that’s a problem. Stick to a predictable cadence and adjust based on engagement. If open rates are dropping, maybe you’re emailing too often or need to re-spark interest. Also, consider timing – for a UK audience, sending during UK business hours (or early morning) might catch them when they’re checking email. There’s evidence that consistency in send time can help your emails become a “expected guest” rather than a surprise.

• Call to Action and Interaction: Encourage interaction in a positive way. Simple things like asking a question that invites a reply (and then actually monitoring replies) can increase engagement. Some companies even say “Hey, add us to your address book to make sure you see our updates” – if a user does add you to contacts, that usually whitelists you in many email clients. You can’t force it, but you can politely suggest it in a welcome email, for example. The more your subscribers act on your emails (open, click, reply, star, move to a folder, etc.), the more inbox providers trust your emails.

• Fresh and Valuable Offers: Especially for e-commerce or SaaS marketing, don’t send the same generic content over and over. Mix it up with genuinely useful stuff – a how-to guide, a success story, insider tips, or a special discount that feels exclusive. If every email is just “Buy our product! Here’s 10% off!” repeatedly, fatigue sets in. Value can also be educational content or entertainment. If subscribers feel there’s something in it for them beyond a sales pitch, they’ll engage more.

Remember, at the end of the day, real humans are on the other side of those emails. If you cater to their needs and interests, you build loyalty. And from a technical standpoint, that loyalty translates into better deliverability metrics (opens, clicks, low complaints) which keep your emails in the inbox. It’s all interconnected. Good marketing equals good deliverability, and vice versa.

Monitor Your Email Deliverability (Use the Right Tools)

You can’t manage what you don’t measure. Part of a holistic approach to staying out of spam is monitoring your email deliverability and catching issues early. Thankfully, there are several great (and often free) tools to help with this:

• Google Postmaster Tools: If you send a significant volume of email to Gmail addresses, this is a must-use resource. Google Postmaster Tools lets you see how Google perceives your emails. After verifying you own your sending domain, you can view data like Reputation (for your domain and IP), Spam Rate (percentage of your emails to Gmail that were marked as spam by users), and Feedback Loop data, as well as Authentication results for your messages. It will even show if you have issues with encryption or if Gmail is seeing a lot of errors. By checking in on Postmaster Tools, you might discover, for example, that your domain reputation is “Low” at Gmail – a clue that you need to work on engagement or list cleanliness specifically for your Gmail recipients.

• Microsoft SNDS (Smart Network Data Services): This is akin to Google’s tool but for Outlook/Hotmail/MSN mail. SNDS provides data on any IPs you own that send to Microsoft addresses. It can show you the filtering results (if your mail is treated as spam or not), complaint rates, and whether your IP is on their internal block list. If you’re sending from a shared IP via an ESP, you might not be able to use SNDS (since you don’t “own” the IP), but some ESPs provide this kind of data themselves. If you do have a dedicated IP, definitely set up SNDS. It’s free; you just need to prove you control the sending IP (usually by receiving an email at the abuse@ or postmaster@ address of your domain).

• MX Toolbox: We’ve mentioned this one a couple of times. MXToolbox is a handy online toolbox for various email and DNS checks. For deliverability, you can use their Blacklists check to scan dozens of public blacklists for your IP or domain. It also has an SMTP diagnostic tool, and can check your DNS records (SPF, DKIM, MX, etc.) for correctness. It’s a quick way to catch if, say, you accidentally got on a blacklist or if an important DNS record has an issue. Set a calendar reminder maybe once a month to do a blacklist check, or use their free monitoring alerts service.

• EasyDMARC (and other DMARC analysers): If you’ve set up DMARC, you will start getting XML reports from various mail providers about your email authentication. EasyDMARC is a tool (with free and paid tiers) that can parse these reports into a human-readable dashboard. It can show you if any sources sending mail as your domain are failing SPF/DKIM, and where your legitimate mail is coming from. This is more about domain security and compliance, but it also indirectly helps deliverability – you might discover, for example, an old system or third-party sending unauthenticated email on your behalf that you forgot to include in SPF. Fixing that could improve your overall authentication alignment (and thus inboxing).

• Other Tools and Services: There are many other deliverability tools out there. For example, we (Digistrat) offer deliverability assessments, GlockApps offer spam testing (sending your email to multiple providers and seeing if it lands in spam), and Validity (Return Path) offers certification and sender score services. You don’t necessarily need all of these, but be aware they exist. One simple (and free) practice: create test accounts on major email providers (Gmail, Outlook.com, Yahoo, etc.) and include them in your campaigns to see where your email lands. If your test Gmail account consistently gets you in spam, that’s a red flag to investigate.

Monitoring tools are your early warning system. They help you answer questions like: Is my sender reputation improving or worsening? Did my latest campaign cause a spike in complaints? Are all my authentication protocols passing as expected? By keeping an eye on these, you can adjust your strategy before things get out of hand. It’s much better to catch a downward trend in reputation early than to find out after two months that half your emails have been junked.

Comply with Email Regulations and Best Practices

While not directly a “filter trigger” in the algorithmic sense, failing to comply with email regulations can get you into trouble and indirectly harm deliverability. Make sure you’re following laws like GDPR (for EU/UK) and CAN-SPAM (for U.S., if you have any U.S. recipients). For UK and European businesses, GDPR and the PECR require you to have consent for marketing emails and to honor unsubscribe requests, among other things. Here’s how compliance helps you stay out of spam:

• Include an Unsubscribe Link in Every Email: This is legally required in most jurisdictions for marketing emails. Beyond legality, it’s a best practice because if someone wants off your list and can’t easily unsubscribe, they’ll hit the “Mark as spam” button out of frustration. That’s much worse for you. Make your unsubscribe link clear (usually in the footer) and easy. Some companies also include a note like “You’re receiving this because you signed up for X. Manage preferences or unsubscribe here.” This reminds the user that they did opt in, reducing the chance they think of you as spam.

• Use a Recognisable Sender Name/Email: Don’t send marketing emails from “[email protected]” if you can help it. Not only is that unfriendly (and against the idea of encouraging replies and engagement), but it can also raise suspicion. Instead, send from a real email address that looks professional, like [email protected] or [email protected]. And set the sender name to your brand or a team member’s name plus brand (e.g., “Alice from MyCompany”). People are more likely to trust and open emails when they clearly know who it’s from. Some spam filters also consider generic no-reply addresses a negative factor because many spammers use throwaway addresses.

• Physical Address in Footer: In the UK and many countries, commercial emails should include the physical mailing address of the business (this is part of CAN-SPAM requirements and good to do under GDPR guidelines too). Having a physical address visible can actually add a bit of legitimacy in the eyes of spam filters – it’s one of those things real companies do that spammers often don’t bother with. It won’t singlehandedly save you from spam, but it’s one more trust signal (and a legal must-do).

• Consent and Preference Centre: We touched on not buying lists and only sending to those who opted in. I’ll reinforce it here: consent is king. If you ever get tempted to add people to your list who didn’t explicitly sign up, resist the urge. Not only can that violate regulations, it almost never ends well for deliverability. Consider implementing a preference centre where subscribers can choose what type of content they want (for example, product updates, newsletters, events, etc.). This way they’re in control and you’re less likely to overwhelm them with unwanted emails – which again leads to fewer spam complaints.

By being a responsible sender and obeying the rules, you not only avoid fines or penalties, but you also show mailbox providers that you’re the “good kind” of sender. Many spam filters incorporate elements of these best practices into their algorithms indirectly (for instance, the presence of an unsubscribe header or a proper from name might contribute to a lower spam score). Plus, if you ever need to appeal to an ISP or ask for help from your ESP’s deliverability team, you’ll be on solid ground if you can show you follow all the best practices.

Consider Sender Reputation and Spam Testing Tools

We’ve already discussed several tools and tactics, but if you’re serious about improving deliverability, you might consider some dedicated testing and reputation services:

• Sender Score (by Validity): This is a popular tool that gives you a score (0 to 100) representing the health of your sending IP address. It’s somewhat analogous to a credit score but for email senders. A higher score means you’re following best practices relative to other senders. While not every mailbox provider uses Sender Score, it’s a useful benchmark. If your sender score is low, it correlates with deliverability issues. Validity (formerly Return Path) also offers certification services – if you meet very strict criteria, some ISPs will deliver your mail to inbox by default. That’s more for large senders, but worth knowing.

• Inbox Placement Tests: Services like GlockApps, or Email Consol allow you to send a test email to a panel of test addresses at various ISPs and then show you whether each instance landed in Inbox, Spam, or was missing. This can be eye-opening. For example, you might find your emails go to inbox on Gmail and Yahoo, but consistently to spam on Outlook. That would tell you to focus on what Outlook’s filters might be seeing (perhaps your IP reputation on Microsoft is bad or some content issue triggers them more). These tests often also give a breakdown of any spam filter analysis (like SpamAssassin score components, etc.).

• Content Spam Filters: There are open-source spam filters like SpamAssassin that assign points for various content and technical aspects. Some inbox providers or corporate mail servers use similar systems. Running your email through SpamAssassin (some tools do this behind the scenes) can point out issues – e.g., if your email is missing a plaintext version, or if certain phrases scored points. While not all filters act the same, checking against a content filter can catch obvious blunders.

• Feedback Loops (FBLs): Major ISPs often provide a feedback loop service where if a user marks your email as spam, the ISP will send a report back to you (or your ESP) with the offending email details. You usually need to register for these (Return Path/Validity or your ESP can help, or some are available publicly like AOL’s). If you run your own mail server, definitely sign up for FBLs. If you use an ESP, they usually handle it and will remove those who hit “spam” from your list automatically. Understanding your complaint rates via FBL is crucial – it’s direct evidence of how users feel about your mail.

Employing these extra tools can take your deliverability efforts to the next level. They’re especially useful if you’ve tried the basics and still can’t pinpoint an issue. They give a peek under the hood of the filtering systems. Just remember, tools provide data – it’s up to you to interpret and act on it. For example, if an inbox test shows spam placement in Outlook, you might then check SNDS or adjust your content and test again. It can feel like detective work, but it’s quite satisfying when you see improvements from changes you’ve made.

Leverage Expert Help if Needed

Email deliverability can get complex, and sometimes you might hit a wall. Perhaps you’ve fixed all the obvious issues and still find your open rates are abysmal due to spam filtering. In such cases, don’t hesitate to seek help from deliverability experts. There are consultants and services whose entire job is to diagnose and fix spam problems.

For instance, Digistrat is a UK-based email marketing and deliverability consultancy that specialises in helping businesses fix spam folder placement and restore sender reputation. If you’re feeling overwhelmed, we offer a free Inbox Scorecard call – essentially a 30-minute one-on-one review of your email setup and reputation. In that session, they can flag unseen risks and give you actionable advice tailored to your situation (no fluff, just practical tips). It’s like a health check-up for your email program, but free of charge. Services like this can be incredibly insightful because they have experience with many clients and can quickly identify “oh, Gmail is junking you because of XYZ, which we’ve seen before.” Feel free to find a time to book in HERE

Engaging an expert doesn’t mean you failed; it just means email deliverability is a specialty and sometimes a fresh pair of eyes can spot issues you might miss. They can help with things like** deep-diving into your DNS records, guiding you through a warm-up plan, liaising with ESP support or ISP postmaster teams**, and more. Especially for SMBs in the UK where you might not have a dedicated email engineer, a consultant can save you time and revenue by fixing deliverability faster.

Whether you use an expert or not, the biggest takeaway is to be proactive. Don’t wait until your sales team says “customers aren’t seeing our emails” or your CEO’s test email went to junk. Regularly review your metrics, use the tools we discussed, and continuously apply best practices.

Conclusion

Keeping your emails out of the spam folder is an ongoing journey, not a one-time task. We’ve learned that stopping emails from going to spam requires a bit of everything: the right technical setup, a strong sender reputation built over time, great content, engaged recipients, and careful monitoring. There truly is no single silver bullet – but the combination of all these efforts will significantly tilt the odds in your favour.

In this guide, we’ve covered why emails go to spam (from authentication issues to spammy content and beyond) and walked through a comprehensive game plan to fix it. By authenticating your emails with SPF, DKIM, and DMARC, you’re showing mailbox providers you are who you claim to be. By maintaining list hygiene and sending only to those who want your emails, you’re building trust and a positive reputation. By crafting emails with genuine value and avoiding the traps of spammy design and language, you’re demonstrating that your communications deserve to be seen. And by leveraging tools and maybe even experts like Digistrat’s free Inbox Scorecard, you’re staying ahead of issues and continuously improving.

It may feel like a lot of work, but remember the reward: reaching your customers’ inboxes consistently. When your emails land in the inbox rather than spam, you’ll likely see higher open rates, more engagement, and better results from your campaigns – whether that’s more sales, sign-ups, or satisfied customers. Every extra percentage of deliverability is a win for your business’s bottom line and brand reputation.

So, implement these changes step by step. Monitor the impact. Don’t be discouraged if it takes a bit of time to see improvement – slow and steady wins the race in the world of email deliverability. With persistence and the right approach, you can escape the spam folder trap. Here’s to seeing your next email campaign land squarely in the inbox where it belongs!

Alternatively, if you would like some help to identify some of your deliverability and email marketing challenges, then please get in touch for a free consultation call with Digistrat – CLICK HERE

Digistrat is proud to be recognised and listed on DesignRush’s B2B Market Place for Email Marketing – Digistrat Consulting’s rating on DesignRush, the industry-leading B2B Marketplace connecting brands with agencies