How to Enable SMTP-ALT Port 2525 on a Smartermail Server
This article will go over how to enable the alternate SMTP port 2525 for submitting mail on a Smartermail server. This should already be enabled by default during server setup, but in some cases it may be missing, or missing from certain IPs.

Issue
You need SMTP to be accessible on port 2525 in addition to port 25 on a Smartermail server.

Resolution
Note that this must be done by a server administrator. If you are a dedicated server customer, you may do this yourself.  If you are a shared hosting customer, you must request that this be configured for you by contacting our support team.  

In SmarterMail 8.x

1. Log into SmarterMail as admin.
2. Go to Settings > Bindings > Ports.
3. If The SMTP (Alternate) port is not created, create it by clicking New and entering in SMTP (Alternate) for the name and 2525 for the port, then click on Save.
4. Go to Settings > Bindings > IP Addresses.
5. Edit each IP address and make sure the following ports are checked: 25, 110, 143, 2525 and then hit Save.
   
6. Using the Plesk Services Manager, restart the SmarterMail Services, if you are unsure how to do this follow the instructions in our article on Restarting Services in the Plesk Services Manager.

In SmarterMail 7 and Earlier

1. Log into SmarterMail as admin.
2. Go to Settings > Defaults > Domain Defaults.
3. Set SMTP Port (Alternate) to be 2525.
   
4. Click Save.
5. Go to Settings > Defaults > Domain Propagation.
6. Check Alternate SMTP Port.
7. Click Propagate Now.
8. Wait 1 minute while the settings are propagated.
9. Using the Plesk Services Manager, restart the Smartermail Services.See Restarting Services in the Plesk Services Manager.