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.
What Is Email Deliverability, Really?
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.
How to Check Your Email Deliverability: A Step-by-Step Guide
1. Run Inbox Placement Tests
Use tools like GlockApps, Mail-Tester, or Email on Acid. These send your email to a variety of real inboxes across Gmail, Yahoo, Outlook and others, and tell you exactly where it landed: inbox, spam, or blocked entirely. Do this regularly across different campaigns to build a picture over time.
2. Check Sender Reputation
Use Google Postmaster Tools, Microsoft SNDS, Talos Intelligence, or SenderScore.org. Look for red flags like low domain or IP reputation, high spam complaint rates, and large volumes of rejected emails.
3. Check Authentication (SPF, DKIM, DMARC)
Use MXToolbox or EasyDMARC to verify you have a valid SPF record, a signed DKIM key, and a published DMARC policy. Start with p=none to monitor, then move to p=quarantine or p=reject once validated.
4. Review Engagement Metrics
Track open rate, click rate, click-to-open rate, spam complaint rate, and unsubscribe rate. If click-to-open is under 10% or complaints are above 0.2%, investigate further.
5. Scan for Spam Traps and Blocklists
Use list validation tools like UseBouncer or ZeroBounce, then check your domain and IP against Spamhaus, Talos Intelligence, and MXToolbox.
6. Audit Your Content
Use Mail-Tester or Litmus to watch for spammy phrases, broken links, no plain-text version, or image-only emails.
What to Do If Your Deliverability Needs Work
Separate email streams by subdomain. Use subdomains for campaigns, billing, and alerts to isolate reputation issues.
Set up and enforce authentication. Ensure you are passing SPF and DKIM for every platform you send from. Monitor DMARC reports and move toward p=reject once validated.
Clean and monitor your list. Run re-engagement campaigns, apply a sunset policy, and suppress inactive or bounced addresses.
Optimise for engagement. Send fewer, more relevant emails. Use segmentation and personalisation to connect better with your audience.
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 deliverability health check with Digistrat to get clarity and control before problems become visible.
