The port number used by the incoming mail server or Common port numbers for incoming mail like 143 and 993 are incoming mail server ports for IMAP accounts, and similarly 110(non encrypted) and 995 for POP accounts.The host name of the outgoing SMTP (Simple Mail Transfer Protocol) server, such as smtp.example.com. Port. The port number used by the outgoing mail server are 25 (or 587)-non encrypted, 587-Secure (TLS), 465-Secure (SSL)