Ehlo is an internet protocol that is used by the the email system in order to begin communication. It is used by the mail server to allows the identification of the sending server and inform the receiving server of the capabilities of the sending server. This allows the sending server to check whether the receiving server supports the necessary protocols with capabilities to receive mail. Ehlo is similar to helo and they are often used interchangeably. They are both used to identify the mail sending and receiving parties. Ehlo is also used to help activate encryption and also inform the receiving server of TLS capabilities.

4 letters

• hole.

3 letters

• hoe,
• leo,
• hel.

2 letters

• el,
• lo,
• he,
• eh,
• hl,
• le,
• lh,
• oh,
• ho.