default value of relayhost in postfix main.cf

gxu · 04-05-2021, 08:24 AM

I am puzzled to see that the "relayhost" parameter of my /etc/postfix/main.cf has been empty all the while sending mail using mailx has been working fine. Does the default value of "relayhost" default to "mailhost"? since "mailhost" is my organization's SMTP server's name.

I am running Suse Leap 15.1

shruggy · 04-05-2021, 09:27 AM

Quote:

Originally Posted by gxu

Does the default value of "relayhost" default to "mailhost"?

Nope. It defaults to empty. But it gets overridden by "relay_transport" and a bunch of other settings. See its description in the manual page.

gxu · 04-05-2021, 01:15 PM

Quote:

Originally Posted by shruggy

Nope. It defaults to empty. But it gets overridden by "relay_transport" and a bunch of other settings. See its description in the manual page.

That's what I thought. But then how could sendmail/mail/mailx work when it is empty? How does it find the MX server to send mail out?