Which TCP port is traditionally assigned as the standard default port for unencrypted SMTP communication between mail servers?

Correct option is B

TCP Port 25 is the standard default port used for unencrypted SMTP (Simple Mail Transfer Protocol) communication between mail servers. SMTP is responsible for sending and relaying email messages across networks.

Traditionally, mail servers use Port 25 for server-to-server email transfer. Although secure alternatives are now commonly used, Port 25 remains the official default SMTP port for unencrypted communication.

Therefore, the correct answer is Port 25.

Important Key Points:

1. SMTP stands for Simple Mail Transfer Protocol.
2. TCP Port 25 is primarily used for mail server-to-mail server communication.
3. SMTP handles the sending and relaying of emails.
4. Port 25 generally supports unencrypted email transmission.

Knowledge Booster:

1. (a) 80: Incorrect because Port 80 is the default port used for HTTP (HyperText Transfer Protocol) web traffic.
2. (c) 110: Incorrect because Port 110 is used for POP3 (Post Office Protocol Version 3) email retrieval.
3. (d) 143: Incorrect because Port 143 is used for IMAP (Internet Message Access Protocol) email access.
4. (e) 465: Incorrect because Port 465 is commonly associated with SMTPS (SMTP over SSL/TLS) for secure email transmission.