Postfix can't send mails externally

Hi everyone,

I installed and configure on Ubuntu 16.04 droplet but it couldn’t send email externally.

I’ve tested this scenarios:

  • Send an internal emails, it works.
  • send an email from gmail or yahoo mail or other email service, it works too, so I receive the email in the appropriate mailbox.

The unique scenario that doesn’t work is when i try to send to an external email services such as google, yahoo, outlook or other site.

Looking into the Postfix logs I got the some different error messages: a. Network is unreachable b. Connetion timeout

Could you please help me? I already opened a ticket for looking into this issue (ports configuration and droplet exceptions) but I didn’t receive any feedback/new about the solution… so I’m considering change my VPS cloud provider.

Could you recommend me any other VPS Could server provider?

Thank you all your help.


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Hi! Can you please post the output of the following command?

nc -z 25

If it does not output Connection to port 25 [tcp/smtp] succeeded!, it’s possible that outbound SMTP is blocked on your droplet. In that case, the support team will be able to unblock it for you!

I am facing the same problem. I run nc ... and no output…

Hi, I’m facing the same issue, but on a Centos7:

Feb 13 18:18:38 xxx postfix/smtp[28162]: 71259434AFB: to=<>, relay=none, delay=150, delays=0.06/0.03/150/0, dsn=4.4.1, status=deferred (connect to[]:25: Connection timed out)

Feb 13 16:34:09 xxx postfix/smtp[27606]: connect to[]:25: Connection timed out

All my Outbound rules are allowed… Can you help?

Btw, running nc -z 25 takes a while and response is empty