When web apps on my VPS use the PHP built-in
550 [PERMFAIL] att.net requires valid sender domain (in reply to RCPT TO command)
MAIL FROM line is something like
<user@myhost> when it should be
<email@example.com>, so AT&T's mail server doesn't like it.
I'm not entirely sure if my
/etc/hostname file needs to be myhost or myhost.com. Any time I try to change it to myhost.com, upon reboot it reverts back to myhost.
I'm at a loss here.
/etc/hostname (according to Google searches) should be just the hostname, not the FQDN. If I type
hostname --fqdn, then I get the FQDN.