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CCC · Email & self-hostingCurated

Self-hosting email: DNS, spam filters and reputation

Summary

davd delivers a reality check on running your own mail server and explains why DNS, deliverability, spam defence and reputation are harder than the actual server software. With email, self-hosting fails more often because of social trust than because of SMTP. Decentralisation only survives if small operators can achieve deliverability in practice.

Ideas

  • Email remains a federated system between independently operated servers.
  • SPF, DKIM and DMARC provide signals about senders and permitted sending paths.
  • Reputation often matters more for delivery than formally correct protocols.
  • Spam filtering requires ongoing observation instead of a one-off configuration.

Insights

  • With email, self-hosting fails more often because of social trust than because of SMTP.
  • Decentralisation only survives if small operators can achieve deliverability in practice.

Recommendations

  • Check forward DNS, PTR, TLS, SPF, DKIM and DMARC before sending the first message.
  • Monitor queues, bounces and reputation continuously.

References

Watch the talk

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