Denied -HELO name

How does one correct this error.
I can send email to this account using gmail with no error.

error from mailer daemon :

I am deeply sorry, but I was not able to deliver your mail to the following addresses:
richllittle@logsol.com : Access denied - Invalid HELO name (See RFC2821 4.1.1.1)
This is a permanent delivery failure. The delivery has been tried 0 times and will not be rescheduled again.

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Hello,

Use the steps from below KB article to set the EHLO Banner:

https://www.axigen.com/kb/show/128

:bangbang: It is recommended that the Ehlo text to be the network FQDN of your machine.

BR