SSL can be used on many ports; for web traffic, the common port is 443.
Gmail is a mail sending application of the web. It uses two ports for SSL and TCL. The port number for SSL is 465 and the port number to TCL is 587.
Gmail uses 2 ports for sending and receiving data. the port number 487 is for SSL. The port number 587 is for TLS.
The default port number for the Internet Message Access Protocol (IMAP) is 143. When using IMAP over SSL/TLS for secure communication, the default port number is 993.
The default port should be 443 but it can be changed.
993 IMAP over SSL or MMP IMAP Proxy over SSL
For EarthLink's email service, the incoming mail server (IMAP) settings are typically set to imap.earthlink.net with port 993 and SSL enabled. For POP3, the incoming server is pop.earthlink.net with port 995 and SSL enabled. The outgoing mail server (SMTP) is smtp.earthlink.net, using port 587 with SSL or port 25 without SSL. Always ensure to use your full email address and password for authentication.
port 636
Gmail uses the technology or the protocols to send mails. It works on port number 487 for SSL. IMAP and SMTP are the protocols used.
The default port number for Internet Relay Chat (IRC) is 6667. However, secure connections using SSL/TLS typically use port 6697. Other ports may also be used for specific IRC servers or configurations, but 6667 is the most commonly recognized.
mail.messagingengine.com IMAP SSL Port 993
A secure certificate (SSL).
Generally port 21 is for FTP 22 for FTP using SSH 990 FTP using SSL