If you’re sending emails and wondering whether they’re actually landing in inboxes, you’re asking the right question: how do I check my deliverability?
In 2025, with mailbox providers enforcing tougher sender requirements, “deliverability” is no longer just a technical metric, it’s a revenue lever. Poor deliverability means you’re effectively invisible, no matter how good your content, offer, or strategy might be.
In this post, we’ll break down exactly how to check your email deliverability – using real tools, practical techniques, and insider benchmarks – and what to do if you spot issues. Bear in mind we wanted to keep the detail relatively light but still useful – our own audits go into much more granular depth etc.
What Is Email Deliverability, Really?
At its core, email deliverability refers to whether your emails actually make it into the inbox – not just whether they were “sent” or “delivered”.
A 99% delivery rate sounds great… until you realise 60% of your emails are in spam or “promotions” folders that no one checks.
Deliverability is affected by everything from sender reputation and list quality, to your email setup and how people engage with your messages.
How We Do It at DigiStrat
If you’re looking for more than a surface-level check, our Deliverability Audits go far deeper than just tool outputs. We combine hands-on technical investigation with a full strategic review, built around our own SENDER Framework.
SENDER stands for:
- Sending setup & authentication
- Engagement drivers
- Nurture sequences & automation
- Data hygiene
- Effective content
- Results measurement
We don’t just identify the issues, we give you a clear roadmap to fix them, and make sure your whole email programme is built to perform long-term, not just hit inboxes this week.
Whether you need a one-off audit or hands-on implementation, we tailor support around your in-house resources and growth priorities.
👉 See our audit services or book a free health check to get started.
Why Deliverability Matters More Than Ever in 2025
In the last 12 months, we’ve seen Gmail and Yahoo enforce new requirements for bulk senders:
- Valid SPF & DKIM authentication
- Aligned From: headers
- A published DMARC policy
- Spam complaint rate below 0.3%
- One-click unsubscribe support
If you’re not meeting these standards, inboxes are closing their doors – fast.
Even legitimate businesses with opt-in lists are being caught out. That’s why monitoring and managing deliverability has become mission-critical.
How to Check Your Email Deliverability: A Step-by-Step Guide
Here’s a structured approach we use at DigiStrat when auditing a client’s email health. You can follow the same process in-house.
1. Run Inbox Placement & Content Tests (Seed Testing)
Use a tool like:
These tools send your email to a variety of real inboxes (across Gmail, Yahoo, Outlook etc.) and tell you exactly where it landed – inbox, spam, or blocked entirely.
Tip: Do this regularly across different campaigns to build a picture over time.
2. Check Sender Reputation (At the Mailbox Level)
To check your sender reputation, use:
- Google Postmaster Tools
- Microsoft SNDS
- Talos Intelligence
- SenderScore.org
Look for red flags like:
- Low domain/IP reputation
- High spam complaint rates
- Large volume of rejected emails
If these tools show you’re in the red, it’s time to act.
3. Check Authentication (SPF, DKIM, DMARC)
Use:
You’ll want:
- A valid SPF record
- A signed DKIM key
- A published DMARC policy (start with
none, move toquarantineorreject)
4. Review Engagement Metrics
Key metrics to track:
- Open rate
- Click rate
- Click-to-open rate
- Spam complaint rate
- Unsubscribe rate
Benchmark: If click-to-open is under 10% or complaints over 0.2%, investigate further.
5. Scan for Spam Traps and Blocklists
Use tools like:
Then check your domain/IP on:
6. Audit Your Content
Use:
Watch for spammy phrases, broken links, no plain-text version, or image-only emails.
What to Do If Your Deliverability Needs Work
Fix #1: Separate Email Streams by Subdomain
Use subdomains like:
news.brand.com(campaigns)billing.brand.com(invoices)info.brand.com(alerts)
Fix #2: Set Up and Enforce Authentication
Ensure you are passing SPF and DKIM for the relevant domains AND for each platform you are sending from.
Monitor your DMARC reports via a tool and over time once you feel comfortable consider moving from p=none to p=reject once everything is validated. Tools like EasyDMARC and Email Consul can help.
Fix #3: Clean and Monitor Your List
- Run re-engagement campaigns
- Apply a sunset policy
- Suppress inactive or bounced addresses
Fix #4: Optimise for Engagement
- Send fewer, more relevant emails
- Use segmentation and personalisation to connect better with your target avatars
- Test subject lines and CTAs
Recommended Tools
| Function | Tools |
|---|---|
| Inbox Placement Testing | GlockApps, Email on Acid |
| Authentication & DMARC | EasyDMARC, MXToolbox |
| List Cleaning | UseBouncer, Neverbounce |
| Reputation Monitoring | Google Postmaster, SNDS |
| Blocklist Checking | Talos Intelligence, Spamhaus |
| Spam Scoring | Mail-Tester, Litmus |
Final Thought: Don’t Wait Until It’s Broken
Deliverability issues are like leaks in a roof – invisible until the damage is done.
Book a free health check or full Deliverability Audit with DigiStrat to get clarity and control.