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Deliverability8 min readJune 27, 2026

Why Are My Emails Going to Spam? 12 Fixes

Emails land in spam for four reasons: authentication, reputation, content, and list quality. Here are 12 concrete fixes, one for each common cause.

You hit send, the email looks fine, and it lands in spam anyway. Frustrating, and usually fixable. Spam placement is rarely one big mistake. It is a stack of small signals: who you are (authentication), how you have behaved (reputation), what you sent (content), and who you sent it to (list quality and complaints). Get those four right and most messages reach the inbox.

Here are 12 concrete fixes, grouped by the four things mailbox providers actually score.

Send Auth SPF DKIM DMARC Reputation IP and domain Content text, links images List valid, no complaints Inbox
Every send runs four gates in order. Fail any one and you slip toward the spam folder.

Authentication: prove the mail is really from you

If a provider cannot confirm who sent the message, it treats it as suspicious. This is the first thing to fix because it is binary and fully in your control.

1. Set up SPF

SPF is a DNS record that lists which servers are allowed to send for your domain. Without it, anyone can forge your address and the receiver knows it. Add a single TXT record naming your sending service, and keep it under the 10 DNS lookup limit or it silently breaks.

2. Sign with DKIM

DKIM adds a cryptographic signature to every message so the receiver can verify it was not altered in transit. Your sending platform gives you a public key to publish in DNS. Turn it on for every domain you send from, not just the main one.

3. Publish DMARC and watch the reports

DMARC ties SPF and DKIM together and tells providers what to do when a message fails. Start at p=none so you can read the aggregate reports without blocking real mail, confirm your legitimate sources pass, then move to p=quarantine and eventually p=reject. Gmail and Yahoo now require DMARC for bulk senders, so this is no longer optional.

Reputation: your sending history follows you

Mailbox providers keep a running score on your sending IP and your domain. A bad score sends you to spam regardless of how clean the message is.

4. Warm up new IPs and domains slowly

A brand new IP with no history that suddenly blasts 50,000 emails looks exactly like a spammer. Ramp volume over two to four weeks, starting small and increasing daily, sending to your most engaged contacts first.

5. Keep volume and timing steady

Wild swings in daily volume look like a hijacked account. Pick a cadence and hold it. If you must scale up, do it gradually rather than 10x overnight.

6. Protect your domain reputation, not just the IP

Reputation now travels with your sending domain too, so switching IPs will not reset a damaged history. The fix is upstream: only send mail people want, which is what the rest of this list covers. For a fuller treatment, see our guide on improve email deliverability.

Content: do not look like the thing filters are trained on

Content filters are pattern matchers. They flag the shape of mail that historically turned out to be junk.

7. Fix the spammy signals in your message

  • Drop the all-caps subject lines and rows of exclamation marks.
  • Keep a sensible text to image ratio. An email that is one giant image with almost no text is a classic spam tell.
  • Always include a working plain-text version alongside the HTML.
  • Avoid link shorteners and mismatched display text that hides the real destination.

8. Use a real, consistent From address

Send from a proper address on your own domain, like [email protected], not noreply@some-random-subdomain. Keep the From name and address stable so recipients and filters recognise you over time.

9. Make unsubscribe obvious and one-click

A clear unsubscribe link plus the List-Unsubscribe header is required for bulk senders to Gmail and Yahoo. Counterintuitively, an easy opt-out improves deliverability: people unsubscribe instead of hitting the spam button, and spam complaints hurt far more.

List quality and complaints: the signal that decides everything

This is where most inbox problems actually start. You can have perfect authentication and clean content and still land in spam if you send to bad addresses or to people who do not want your mail.

10. Verify your list before you send

Sending to dead mailboxes drives up your bounce rate, and a high bounce rate is one of the strongest spam signals there is. Verifying removes invalid addresses, spam traps, and risky catch-all domains before they ever cost you. This is the single highest-leverage fix on the list. Run your file through a free email verifier and clean it first. More on the mechanics in reduce email bounce rate.

11. Only email people who asked

Purchased and scraped lists are full of traps and uninterested recipients who mark you as spam. Use confirmed opt-in so every address chose to hear from you. Quality of consent beats raw list size every time.

12. Prune dead weight and watch complaints

Contacts who have not opened anything in six months drag down your engagement score, which providers read as a sign your mail is unwanted. Run a re-engagement campaign, then remove the non-responders. Keep your spam complaint rate under 0.1 percent, the threshold Gmail and Yahoo now enforce. Regular email list hygiene keeps this in check.

Problem areaQuickest fixImpact
AuthenticationSPF, DKIM, DMARC in DNSHigh, and binary
ReputationWarm up, steady volumeHigh, slow to repair
ContentReal From address, text versionMedium
List qualityVerify and opt-in onlyHighest

Where to start

If you only do three things today: publish SPF, DKIM and DMARC, verify your list, and stop emailing people who never open. Those cover the gates that catch most senders. The rest is maintenance.

FAQ

Why do my emails go to spam for some recipients but not others?

Each mailbox provider scores you separately and factors in that individual user's behaviour. If your Gmail contacts open and reply while your Outlook contacts ignore you, Gmail keeps inboxing you and Outlook starts filtering. It usually points to a reputation or engagement gap with one provider, not a broken setup.

How long does it take to recover a sending reputation?

Authentication fixes take effect as soon as DNS propagates, often within a day. Reputation is slower. Expect two to six weeks of consistent, clean sending to a verified and engaged list before providers trust you again. There is no instant reset, and switching IPs does not erase domain history.

Does email verification actually help inbox placement?

Yes, indirectly but strongly. Verification lowers your bounce rate and keeps you away from spam traps, which are two of the heaviest negative signals. Cleaner sends mean better reputation, and better reputation means the inbox. See the complete guide to email verification for the full picture.

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Why Are My Emails Going to Spam? 12 Fixes | Prime Verifier