One you create an Email User in the Plesk Control Panel, you can locate your mail server settings at the following location:
Go to Websites & Domains in your Windows Plesk Control Panel> the domain whose email you want to access via an email client > Mail Accounts > the 
icon.
Supported incoming mail protocols
POP3, POP3 over SSL/TLS, IMAP, IMAP over SSL/TLS
Supported outgoing mail protocols
SMTP, SMTP over SSL/TLS
To connect via POP3 securely over SSL/TLS, use port 995.
To connect via IMAP securely over SSL/TLS, use port 993.
To send messages via SMTP securely, use port 465.
To send Messages using scripts from your website use Port 25.
Note: We force a secure TLS connection on ports 25 and 110.
