I want to host my own mail server and in order to do so I've installed Postfix 2.7.0 and Dovecot 1.2.9 on Ubuntu Server 10.04.
One big problem I face right now is that Google SMTP servers reject my mail ONLY WHEN
it is being sent remotely. Strange, right?
So if I telnet localhost 25
, then issue AUTH LOGIN (not an open relay of course) then send the mail I get a status = sent
and I actually receive
the mail message in my Gmail's account Inbox. Works like a charm.
On the other hand, if I want to send the mail from a remote host, I use:
openssl s_client -connect mail.mydomain.com:465
Then I issue AUTH LOGIN, the login process is successful. So I don't have a problem communicating with my server. I can see what happens in the log files. But when I try to send mail like this, Google replies:
Our system has detected an unusual rate of 421-4.7.0 unsolicited mail originating from your IP address. To protect our 421-4.7.0 users from spam, mail sent from your IP address has been temporarily 421-4.7.0
Why Google accepts my mail if being sent locally but rejects it when I openssl
to my server and send it remotely?
It's like Postfix on my server makes Google aware of how email got to it in the first place and this way enables Google to reject mail that was not sent locally.
Does this make any sense to you, guys?