Why Your Emails Go to Spam: 10 Deliverability Issues and How to Fix Them
When mail lands in spam, the cause is almost always one of a handful of technical issues. Work through this list from top to bottom.
1. Missing or failing SPF
No SPF record, or one that doesn't cover your actual sending service. Check with the SPF Validator.
2. No DKIM signature
Unsigned mail scores worse everywhere and cannot pass DMARC alignment for forwarded messages. Verify your selector with the DKIM Validator.
3. No DMARC record
Gmail and Yahoo now require DMARC for bulk senders. A minimal v=DMARC1; p=none; rua=mailto:you@domain is the floor.
4. Blacklisted IP
Your sending IP may be on Spamhaus, SpamCop or Barracuda — often inherited from a previous user of a cloud IP. Run the Blacklist Checker.
5. Missing reverse DNS
The sending IP must have a PTR record matching your mail hostname. Confirm with the Reverse DNS tool.
6. Wrong or unreachable MX setup
Receivers distrust domains that can't receive replies. Verify with the MX Lookup.
7. No TLS on the mail server
Servers without STARTTLS are penalized. Test ports and TLS with SMTP Diagnostics.
8. Sudden volume spikes
Warm up new IPs and domains gradually — reputation systems treat spikes as a spam signature.
9. Spammy content and broken lists
High bounce rates from stale lists damage reputation faster than any content filter. Clean your list and honor unsubscribes immediately.
10. Expired SSL on links
Links pointing at sites with invalid certificates raise phishing suspicion. Check yours with the SSL Checker.
Run the Domain Health Score for a combined report covering most of these in one click.