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= ptrcnull.me =
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writeups and other stuff

Mail DNS Setup

Since I always struggle with DNS records for mailservers… here are some examples:

DMARC

_dmarc TXT "v=DMARC1; p=none; rua=mailto:dmarc@domain.tld"
  • v - version of DMARC (DMARC1)
  • p - policy (none, quarantine, reject)
  • rua - URI for agreggate reports (comma-separated)
  • ruf - URI for failure reports (comma-separated)

SPF

@ TXT "v=spf1 mx -all"
  • v - version (spf1)
  • mx - allow emails from servers specified in MX records
  • -all - don’t allow from everyone else