I live and breath email. Sending email requires SMTP. I have been a fan of SMTP since 1993. HELO is an important part, “The HELO command is an older one and can be used if only basic functionality is required. If more advanced functionality is required the client should logon with the EHLO command instead. EHLO is a newer one and puts the server in an extended mode and more advanced commands can be used. Most SMTP servers today support the EHLO command.”
