I've scanned my mail server and got a warning about open SMTP relay. I'm a little confused because I read emails only trough imap. This is the list of open ports:
22/tcp open ssh
25/tcp open smtp
80/tcp open http
143/tcp open imap
220/tcp open imap3
Yes, smtp is open, but if I try to send an email trough my mail server (eg mail.tld.com) with an email address that has a different domain (eg email@example.com
) I get an error -- no mail is relayed.
Am I missing something?
How do I find out what SMTP daemon is used?