Guide
Why is my email going to spam?
Nine times out of ten it's email authentication. Here are the real causes, how to diagnose them, and how to fix it.
Run a free deliverability check →The most common causes
By far the most common cause. If receivers can't verify your mail is really from you, they filter it. This is the first thing to check.
Since February 2024, Google, Yahoo and Microsoft require bulk senders to publish DMARC. Without it, your mail is far more likely to be filtered or rejected.
A single spam complaint or a compromised account can get you listed on Spamhaus or similar. Blacklisted senders go straight to spam.
A new domain or IP with no history is treated with suspicion. Sending a large volume suddenly (without warming up) triggers filters.
Trigger words, misleading subject lines, link shorteners, image-only emails and broken HTML all raise your spam score.
For bulk mail, a missing one-click unsubscribe and emailing stale or purchased lists generate complaints that tank your reputation.
If your sending IP has no matching PTR record, or your visible From domain doesn't align with what passed SPF/DKIM, receivers get suspicious.
How to diagnose it
- 1Run a free health check on your domain — it flags failing SPF, DKIM and DMARC in seconds.
- 2Check whether your domain or sending IP is on a blacklist (we monitor Spamhaus and SpamRats).
- 3Turn on DMARC reporting to see exactly which sending source is failing authentication.
- 4Send a test to a Gmail, Outlook and Yahoo address and check the headers for SPF/DKIM/DMARC = pass.
How to fix it
Fix authentication first: publish or repair your SPF, DKIM and DMARC records so all three pass and align. Then request delisting if you're on a blacklist, warm up any new domain or IP gradually, and clean up your content and mailing lists. Most spam-folder problems disappear once authentication is solid.
Find out why in seconds
Run a free scan to see exactly which records are failing — then let DomainHealthPro monitor them so it never happens again.