NDR from one domain

Lately we have been getting the following NDR when sending email to a particular domain:

user@domain.com 16/10/2008 11:46 a.m.
The recipient could not be processed because it would violate the security policy in force
<domain.com #5.7.0 smtp;550 5.7.0 Access Denied>

The emails seem get through if we forward our mail through our ISP SMTP server.

What are we doing wrong?
pAceMakerNZDesktop Support Asked:
Who is Participating?
bevhostConnect With a Mentor Commented:
Try this tool and see if it picks up any errors with your server details.


Amit BhatnagarConnect With a Mentor Technology Consultant - SecurityCommented:
It seems the Target Domain has blocked your IP Address. Have you tried talking to the Domain Admin to see if this is actually the case.

It is quite normal when sometimes machines get infected with Virus or people try spamming (Bulk Mailing) using tools.
pAceMakerNZDesktop Support Author Commented:
No errors - all fine

I will contact their admin and go from there. Thanks for the input.
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How big is the email you are sending? Could be a size restriction on that mailbox you are emailing.
pAceMakerNZDesktop Support Author Commented:
Don't think it's a size issue. We have sent both simple text and files for testing with no change.
pAceMakerNZDesktop Support Author Commented:
I haven't heard from the other administrator. I have done more tests and it would seem that it's not on our side.
Thanks for the help
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