577 unable to accept message

[BenyG]

Dear all,

An external company is having trobule emailing us. They only have difficulty in emailing our company and not any others. This occurs with more then 1 acc at our end.

From the initial look at this we could say that it is not our systems as all other emails ok however the other compny is doing the same.

We can send to them ok.

The error message in the bounce is:

The email address could not be found. Perhaps the recipiant moved to a different e-mail organisation, or there was a mistake in the address. Check the address and try again.
< gatekeeper2.externalcompany.com #2.1.5 smtp; 577 5.7. Unable to accept mesage>


One thing of note is that the friendly-text is the same as a 550 (unknown user) error, but it is a 577.

I have tried researching a 577 error but I have got nowhere.

Any ideas?

Ben

Benjamin

 

[ShackDaddy]

Benjamin, I would focus on any anti-spam software you have running at your location, on your mail server. You might see if you can make an exception for their domain, since other factors (their originating IP, the existence (or non-existence) of an RDNS record for them, etc. may lend to a bounce from your server, and typically anti-spam software uses a generic bounce message back to the recipient to keep them from being able to analyse the reason and hone their technique. Which is good when you're dealing with spam, but not when it's a business partner you are blocking.

ShackDaddy