add port to smtp

Morning,

The service ports interface available in the panel doesn't change any configuration parameter in the services... That interface only allow you to add ports which are already configured in the services.

Now about your question

Firstly, I'm wondering your needs to use a port such as 2525.... Generally, in mail clients, we use the submission port (587). The port 25 should be used only by servers. You shouldn't use the port 25.

Now, if you need really setup another port (for which purpose exactly?) you must modify the postfix configuration but frankly, you should really avoid to play with the postfix configuration without learning a bit more.

Well, in the /etc/postfix/master.cf file, you can add the following line:

below the following line:

and restart postfix: service postfix restart, which will result to

Then, you should be now able to use the port 2525 in your mail client. However, be aware that this change will be gone on each i-MSCP update/reconfiguration. Best would be to use a listener file to inject that line (and eventually, remove the one that belong to default submission port (587)).