Self-Hosted Mail Server on a VPS — The Honest Requirements

What it really takes to run your own mail: rDNS/PTR, port 25 policy, IP warm-up, SPF/DKIM/DMARC, and which NovaVPS flags are practical for it.

长文正文为英文。页头、目录与结账已翻译。

The three non-negotiables

1) PTR must match your HELO. Every NovaVPS VPS ships with editable rDNS — set the PTR to your mail hostname before the first send. 2) Port 25 must be open. It is, on our VPS and dedicated lines — no unblocking tickets. 3) Authentication records must exist: SPF, DKIM and DMARC published in DNS for your sending domain.

Warm-up is physics, not marketing

A fresh IP with no reputation lands in spam no matter whose network it is. Start with low volume to engaged recipients, keep bounce rates under a few percent, and raise volume over weeks. Big receivers score domains and IPs separately — your domain reputation travels with you even across IPs.

Stack suggestions

• Mailcow or Mail-in-a-Box for an all-in-one start; Postfix+Dovecot+Rspamd for a hand-rolled stack.
• Business or Pro VPS handle typical personal/domain mail loads fine; storage is not the bottleneck — reputation is.
• Separate transactional sends from personal mail on different identities/IPs.