I just set up my first ever email server and I’m proud of myself! 😊 Do you have any advice to avoid common problems? I mean something beginners often do that they shouldn’t. Thanks!
I just set up my first ever email server and I’m proud of myself! 😊 Do you have any advice to avoid common problems? I mean something beginners often do that they shouldn’t. Thanks!
What’s the reason for using IPs instead of domain names for SPF and MX?
Because it’s the simplest form of mechanism for SPF, and the most understandable in my opinion.
aandmxmechanisms are justip4/ip6with extra resolving steps and more complex rules. For a selfhosted setup where you only have a single IP address, this is the most straightforwardAs an example, try to guess which one of these SPF records will or will not pass SPF, given that the IP address sending emails is 1.2.3.1:
$ORIGIN domain.tld. $TTL 1d @ SOA pluto.domain.tld. admin.domain.tld ([…]) NS pluto.domain.tld. NS saturn.domain.tld. MX 10 mx.domain.tld. A 1.2.3.5 TXT "v=spf1 a -all" TXT "v=spf1 mx -all" TXT "v=spf1 ip4:1.2.3.1 -all" jupiter A 1.2.3.1 pluto A 1.2.3.2 saturn A 1.2.3.3 venus A 1.2.3.4 mx CNAME jupiter.domain.tld.