can't send email (connection time out)

[Bog500]

I have a dedicated server from OVH running CentOS 7.4 with WHM cpanel 68.0.28

I'm able to receive email just fine, but I can't send any.

I've already searched this forums for similar problem but none of the solutions worked for me

I always get the same error "Connection timed out", even when sending the email from the user root in putty

Here is a sample from exim_mainlog

2018-02-03 20:00:53 1ei542-0002JN-Lf H=aspmx4.googlemail.com [74.125.206.26] Connection timed out
2018-02-03 20:03:00 1ei542-0002JN-Lf H=aspmx5.googlemail.com [108.177.119.26] Connection timed out
2018-02-03 20:03:00 1ei542-0002JN-Lf == [email protected]****.com R=lookuphost T=remote_smtp defer (110): Connection timed out
2018-02-03 20:03:00 1ehi1C-0003I1-15 Sender identification U=**** D=****.ca [email protected]****.ca
2018-02-03 20:03:00 1ei7LC-0005V8-6B Sender identification U=**** D=****.ca [email protected]****.ca
2018-02-03 20:05:08 1ei7LC-0005V8-6B H=alt2.aspmx.l.google.com [209.85.203.26] Connection timed out
2018-02-03 20:05:10 SMTP connection from [127.0.0.1]:48171 (TCP/IP connection count = 1)

I did a test using telnet on port 25, 110 and 587 and I'm able to connect to remote servers on those ports


CSF firewall is not installed nor any other


SMTP restriction is disabled


Prevent “nobody” from sending mail is turned OFF


I reseted Exim Configuration Manager to default settings

I don't know what else to check...

 

[Bog500]

I contacted OVH and they say they aren't blocking the emails, that I should contact Google.. that doesn't seem right because it's not just gmail, but hotmail and yahoo too and every single test we have done to other domains as well.

 

[cPWilliamL]

It appears that gmail is blocking your mailserver. Perhaps you've excessively forwarded mail(possibly spam) to gmail or you have a cron job that is excessively sending mail to gmail.

You can confirm where the block is occurring by performing a traceroute:

# traceroute -T alt1.gmail-smtp-in.l.google.com. -p 25

If it were a block within your server, it would die at the first hop. If it were a block by your host, it would die within the first ~5 hops. If it's a block at gmail, it will die much further down the line.