// REFERENCE
Port 587 (SMTP submission)
Protocol: TCP
Service: Submission
Low risk
The standard port for clients to send mail, with authentication and STARTTLS. It's the one to set in your mail client (not 25, which is server to server).
Related tools
Work with this in:
Related
25
Port 25 (SMTP) 110
Port 110 (POP3) 143
Port 143 (IMAP) 465
Port 465 (SMTPS) 993
Port 993 (IMAPS) 995
Port 995 (POP3S)
Port 25 (SMTP) 110
Port 110 (POP3) 143
Port 143 (IMAP) 465
Port 465 (SMTPS) 993
Port 993 (IMAPS) 995
Port 995 (POP3S)
Assignments per the IANA port registry. Educational content.