110ppop3: the receiving port of the mail client (Outlook, Foxmail, smart phone, etc.). ).
6080 Webmail: the default web http port for browsers to access Winmail can be changed to the standard 80. Refer to Changing the Network Mail Port.
The above ports are necessary for general mail systems, and the following ports are also recommended to be opened.
465 smtp tls: Encrypted smtp port, which is used by many new mail clients by default.
587 smtp: another outgoing smtp port, used for some mail clients (iPhone, iPad, etc. ) default.
995 pop3 tls: Encrypted clients receive pop3 port, which is used by some mail clients by default.
143 imap: the receiving port of the client. Unlike the pop3 network protocol, most mail clients support it. Refer to imap Baidu encyclopedia.
993 imap tls: Encrypted imap port, which some mail clients use by default when choosing imap protocol.
6443 webmail: encrypted web https port, which can be changed to standard 443.
Ports to be mapped to NAT ports on firewalls or routers are all tcp protocols. If there is a software firewall on the mail system server, it should also be turned on.
The above ports are the entry ports (entry ports) of the external network, and external restrictions (exit ports) are generally not recommended.