Why Are My Emails Going to Spam? 9 Causes and Fixes
When email lands in spam, the cause is almost always one of a handful of things. Work through them in this order — the first few are quick to check and fix.
1. Authentication is missing or broken
Receivers expect SPF, DKIM and DMARC. If any are missing, misconfigured or not aligned with your From domain, you start at a disadvantage.
Check: Run the Domain Health Check. Then send yourself a message and paste its headers into the Email Header Analyzer to see the actual spf=, dkim= and dmarc= results the receiver recorded.
Fix: Follow our SPF, DKIM and DMARC setup guide.
2. SPF is over the 10-lookup limit
Each tool you add to SPF adds lookups. Past 10, SPF returns a permanent error — and it fails silently.
Check: SPF Checker. Fix: remove services you no longer use, or move some senders to a subdomain.
3. DKIM is published but not signing
A common mistake: the DKIM record is in DNS, but signing was never switched on in Google Workspace or Microsoft 365. Headers will show no DKIM signature from your domain.
4. High bounce rate
Sending to addresses that don’t exist tells receivers you don’t know your recipients.
Check: Bounce Rate Calculator. Fix: verify lists before sending, and remove hard bounces immediately. Aim to keep total bounces under about 2%.
5. Spam complaints
When recipients click “Report spam”, it hurts quickly. Gmail asks senders to stay below a 0.3% spam rate.
Fix: tighten targeting, make it easy to opt out, and stop emailing people who aren’t engaging.
6. Too much volume, too fast
New domains and mailboxes have no reputation. Sending hundreds of messages on day one looks like a spammer.
Fix: warm up gradually and keep cold volume to roughly 20–50 emails per mailbox per day. See How Many Cold Emails Can You Send Per Day?
7. Domain or IP reputation problems
If your domain or sending IP is on a blocklist, or has a poor history, filtering gets stricter. Shared IPs on cheap SMTP services can carry other people’s bad reputation.
Fix: check major blocklists, request delisting once the cause is fixed, and consider dedicated infrastructure for important streams.
8. Content and formatting
Content matters less than reputation, but it still matters. Things that hurt:
- Link shorteners and many links in a cold email
- Large images with little text
- Tracking pixels and link tracking on brand-new domains
- Misleading subject lines
Fix: write plain, short, specific emails. For cold outreach, consider sending without open tracking.
9. Missing List-Unsubscribe for bulk mail
Gmail and Yahoo require bulk marketing senders to support one-click unsubscribe (List-Unsubscribe and List-Unsubscribe-Post headers). The Email Header Analyzer shows whether yours are present.
A quick diagnostic routine
- Domain Health Check on your sending domain
- Send to a personal Gmail and Outlook account; analyze both sets of headers
- Calculate your bounce rate for the last campaign
- Reduce volume per mailbox while you fix issues
Once everything is fixed, keep it fixed. Records drift, domains expire and new tools get added. FeedPipeline Monitor watches all of it for you.