“How to check helo” refers to the process of verifying the validity of a HELO (Hostname Extension for Local-Use) command in an SMTP (Simple Mail Transfer Protocol) transaction. When an SMTP client initiates a connection with an SMTP server, it sends a HELO command to identify itself. The server responds with an acknowledgment, indicating whether the HELO command was accepted or rejected.
Checking the HELO command is important for several reasons. First, it helps to prevent spoofing attacks, where an attacker sends emails with forged sender addresses. By verifying the HELO command, the server can ensure that the sender’s hostname matches the IP address of the connecting client. Second, checking the HELO command can help to identify and block spam emails. Spammers often use forged HELO commands to bypass spam filters. By verifying the HELO command, the server can help to reduce the amount of spam that reaches users’ inboxes.
