What is the default TCP port number used by SMTP for email submission with STARTTLS?
Options
A.
25
B.
587
C.
110
D.
More than one of the above
E.
None of the above
Correct Answer (Detailed Explanation is Below)
B.
587
Detailed Explanation
Explanation:TCP port 587 is the standard port for email message submission, commonly using STARTTLS to upgrade the connection to TLS encryption. Port 25 is traditionally used for mail server-to-server transfer.