If your email suddenly started landing in spam, it’s almost always one of a handful of fixable technical issues — not bad luck. Since Gmail and Yahoo tightened their bulk-sender rules, authentication that used to be “nice to have” is now enforced.
Run your domain through the free checker first, then work down this list.
1. Missing or broken authentication (most common)
Receivers check three records:
- SPF — which servers may send for your domain. You must publish exactly one record, and it should end in
~allor-all. - DKIM — a cryptographic signature proving the message wasn’t altered. Your email provider gives you a key to publish.
- DMARC — ties SPF and DKIM together and tells receivers what to do with failures.
The checker flags exactly which of these is missing or misconfigured. If you have no DMARC
record yet, generate one with the DMARC generator and start at
p=none.
2. New domain with no reputation
A brand-new sending domain has no track record, so providers are cautious. Warm it up: send small volumes to engaged recipients first and ramp slowly over 2–4 weeks. Cold-email platforms automate this — if that’s your use case, a tool with built-in warm-up saves weeks.
3. Dirty list and high bounces
Sending to invalid addresses spikes your bounce rate and wrecks reputation. Verify your list before big sends to remove dead addresses. (We may earn a commission from list-verification tools we link to — see our disclosure.)
4. Spammy content and missing unsubscribe
Gmail/Yahoo require a one-click unsubscribe for bulk mail. Avoid spam-trigger phrasing, keep a healthy text-to-image ratio, and always include a working List-Unsubscribe header.
Fix it in order
- Run the checker and fix SPF, DKIM, DMARC.
- Publish a DMARC record and review reports.
- Warm up new domains; verify your list.
- Add one-click unsubscribe and clean up content.
Most “in spam” problems disappear once authentication is correct — start there.