Which Port Is Used for Secure Email Submission?

Which of the following ports is used for secure email?

  1. 25
  2. 110
  3. 143
  4. 587 Source Reference Answer

Community Votes

D
100%

100% of anonymous learners picked answer D. Votes are pick records left by other test-takers — they are not the verified answer.

Community Insight

Tests recognition of modern secure email ports versus legacy plaintext alternatives, with the common trap being the assumption that port 25 handles all secure email traffic.

Port 587 is the industry-standard port for secure email submission using TLS encryption. Community consensus strongly confirms it as the correct answer, distinguishing it from legacy unencrypted protocols.

Option A (Port 25) is frequently selected because it is historically tied to SMTP, but it lacks built-in encryption and is reserved for unsecured server-to-server relaying rather than client access.

Community Discussion (3 comments)

Intel_Geek 👍 6 Selected: D
Port 25 is for SMTP, now considered insecure Port 110 is associated with POP3 which retrieves emails but is only secure with additional encryption Port 143 is associated with IMAP, without encryption Port 587 is the secure version of SMTP and uses TLS encryption
HeatSquad77 👍 1 Selected: D
D. simple mail transfer protocol (SMTP) Application protocol used to send mail between hosts on the Internet. Messages are sent between servers over TCP port 25 or submitted by a mail client over secure port TCP/587.
chupapi_001 👍 4 Selected: D
The correct answer is D: Port 587.

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Expert Analysis

Why the Answer Is Correct

Port 587 is officially designated for mail submission and mandates STARTTLS encryption by default, ensuring credentials and message content remain protected during transmission. CompTIA Network+ prioritizes this modern standard to reflect current cybersecurity best practices for endpoint-to-server communication.

Why the Other Options Are Wrong

Port 25 facilitates traditional SMTP routing but operates in plaintext, making it unsuitable for direct client connections. Port 110 represents legacy POP3, which transmits emails without encryption unless upgraded to the secure variant on port 995. Similarly, port 143 handles IMAP retrieval but lacks the inherent security provided by IMAPS on port 993.

Community Comment Notes

Examiners and users alike emphasize that port 587 leverages TLS encryption specifically for secure client submissions, clearly separating it from older protocols [1]. Multiple contributors clarify that while port 25 remains functional for infrastructure routing, it is definitively classified as insecure for modern usage [3]. The unanimous voting pattern demonstrates strong candidate alignment with official exam objectives regarding encrypted network services.

Official Reference

Exam Strategy

Always pair legacy ports with their secure equivalents when reviewing exam objectives (e.g., 587 replaces 25, 993 replaces 143, 995 replaces 110). If a question specifies 'secure,' 'TLS,' or 'client submission,' immediately discard plaintext options and select the encrypted counterpart.

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