CREST Practitioner Security Analyst (CPSA) Practice 2025 - Free CPSA Practice Questions and Study Guide

Port 25 is commonly associated with the Simple Mail Transfer Protocol (SMTP), which is the standard protocol used for sending emails over the Internet. This protocol allows email servers to communicate with each other and facilitates the sending of messages from a client to a server or between servers.

Understanding the significance of port 25 is crucial, especially in email transmission, where it typically handles outbound SMTP traffic. This port remains an essential part of the email infrastructure, despite the rise of other ports like 587 for secure mail submission.

Other protocols and ports serve different purposes, making their association with port 25 incorrect. For example, FTP (File Transfer Protocol) generally utilizes ports 20 and 21 for transferring files, while SSH (Secure Shell) typically operates over port 22, primarily for secure remote logins. UDP, on the other hand, is a communication protocol used for transferring data, not specifically tied to port 25 or to SMTP in any way. Understanding these distinctions is key to grasping network protocols and their respective roles in Internet communications.