Can not send messages - Helo command rejected: HELO_DYNAMIC Generic / dynamic helo/ehlo is not allowed here

After sending the mail I get an error (return receipt) something like this:

Error transferring to mail.domainname.zz; SMTP Protocol Returned a Permanent Error 554 5.7.1 : Helo command rejected: HELO_DYNAMIC Generic / dynamic helo/ehlo is not allowed here

How do I fix this error?

Subject: Telnet

You may want to try a telnet conversation from within your environment as well as from the outside.Issue a helo j and see what response you get back. * The J can be anything but there has to be something after the helo command.

This may be due to the recipients security settings, or it may be your DNS provider.

A typical SMTP conversation includes:

Connection on Port 25

Helo command

Mail from:

RCPT to:

Data command

period to end conversation

Good luck