Production checklist
Verify ownership of the From domain. Publish the supplied DKIM record and authorize the return-path infrastructure through SPF.
Domain authentication
Domain authentication
Guided DKIM, SPF, and DMARC setup before production sending is enabled.
Authentication terminology
Postline DKIM-signs messages. SPF is an authorization policy published in DNS. DMARC evaluates alignment between the visible From domain and an authenticated SPF or DKIM identity; SPF and DMARC are not applied as message signatures.
Delivery outcomes
A recipient server accepting a message does not prove inbox placement. Treat accepted, deferred, hard bounce, soft bounce, complaint, suppressed, spam placement, and inbox placement as different outcomes.
Current access model
Current dashboard keys use srs_live_. Before a customer From-domain is verified, use the shared sandbox sender only for project-member recipients. After DNS verification, external sending is governed by plan quotas, suppression, recipient throttles, and abuse controls. A 202 response means queued, not delivered.
DKIM postline1._domainkey.example.com TXT "v=DKIM1; k=rsa; p=<generated public key>"
SPF example.com TXT "v=spf1 include:srs-postline.com ~all"
DMARC _dmarc.example.com TXT "v=DMARC1; p=none; rua=mailto:dmarc@example.com"