4 ms·
https://tools.ietf.org/html/rfc5321#section-2.3.5 https://tools.ietf.org/html/rfc5321#section-2.3.5
by AdamGibbins 6y ago
https://tools.ietf.org/html/rfc5321#section-2.3.5 https://tools.ietf.org/html/rfc5321#section-2.3.5
- cedilla 6y agoDo MTAs actually do it though?
- e12e 6y agoYes? http://postfix.1071664.n5.nabble.com/MX-lookup-fallback-to-A-td84070.html http://postfix.1071664.n5.nabble.com/MX-lookup-fallback-to-A... Note that odds are probably low today of anything listening on port 25 if no mx record is set up, I'm guessing (I'm guessing most people that setup an smtp server also sets up mx and a handful of records in dns).