Port 25 SMTP external access

August 18, 2015 10.5k views
Ubuntu Server Optimization Email DigitalOcean System Tools

How can I unblock port 25 for external access? Does digitalocean block this port by default?

2 Answers

On some new accounts port 25 may be blocked by default. This block can be lifted as long as your account has no history of abuse by opening a ticket with our support team from the control panel or by emailing support@. They will verify for you whether a block is in place and can remove it if one is present.

Port 25 Direct Injection is the ability to communicate with a mail server directly not using MX records. This happens when access to Port 25 for SMTP traffic is not restricted. Best email security practice is to restrict Port 25 to only accept from trusted IP’s.

Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 127.0.0.1:25 0.0.0.0:* LISTEN 6427/master

How to set this restriction properly ?

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