Access denied – Invalid HELO name (See RFC2821 4.1.1.1)
If your Exim mail logs show the following error: Access denied – Invalid HELO name (See RFC2821 4.1.1.1) This means that the sending server’s HELO/EHLO hostname is invalid or misconfigured according to the SMTP protocol requirements. What is HELO / EHLO? When an email server connects to another via SMTP, it introduces itself with the … Read more