DNS Records You Need
SPF Record (TXT record for your sending domain):
v=spf1 include:_spf.postmta.com ~all
DKIM Record (TXT record — PostMTA generates the key):
postmta._domainkey IN TXT ( "v=DKIM1; k=rsa; p=YOUR_PUBLIC_KEY" )
DMARC Record (TXT at _dmarc.yourdomain.com):
v=DMARC1; p=quarantine; rua=mailto:dmarc@yourdomain.com; pct=100
PostMTA Authentication Features
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Automatic DKIM signing — Per-domain keys, rotated automatically
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SPF alignment — Strict alignment mode available
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DMARC reporting — Aggregate reports in dashboard
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Failover handling — Route around ISP blocks
Testing Your Setup
Use these tools to verify:
- mail-tester.com — Full spam score analysis
- mxtoolbox.com — DNS record checks
- postmta.com/dashboard — Delivery analytics
Configure PostMTA authentication →