Which ports need to be open for sending and receiving mail?

To send and receive email, the primary ports that need to be open are TCP port 25 for SMTP (Simple Mail Transfer Protocol) used for sending mail, and TCP port 143 for IMAP (internet Message Access Protocol) or TCP port 110 for POP3 (Post Office Protocol) used for receiving mail. Additionally, secure connections often utilize TCP port 587 for SMTP with encryption and TCP port 993 for IMAP over SSL. Ensuring these ports are open allows for proper email communication.