The telnet 25 command is executed to connect to a remote device via port 25, which is intended for SMTP services, typically for email server interactions. However, it's an insecure protocol and has largely been replaced by more secure methods like SSH.
The command telnet 25 initiated on a workstation is used to establish a non-secure connection to a remote system or device on port 25, which is commonly designated for SMTP (Simple Mail Transfer Protocol). SMTP is used for sending emails, which suggests that the network administrator is attempting to manually connect to a mail server for testing or configuration purposes.
Telnet facilitates the administrator to communicate with the server using SMTP commands, enabling them to send emails directly through the terminal, diagnose issues, or manage server settings. However, it's important to note that Telnet sends information, including potentially sensitive details like passwords, in plaintext, which can be insecure. The use of Telnet has been largely superseded by secure alternatives such as SSH (Secure Shell).