Exchange Error

[hanerggyn]

Can you tell me why I am getting this message when emails are sent out? It doesn't do it to all emails, just some of them. We have Exchange 2003. Here is the message:

You do not have permission to send to this recipient. For assistance, contact your system administrator.

[computerfox]

I would do as it says and contact the administrator.
If you are the administrator, check the settings that you put on it and you might want to consider upgrading the exchange server. That would be a great 1 or 2 year project for your team. Is it when you are attaching a large file? Is the domain you are sending to on the black list?

[finlaywilson45]

I would pay particular attention to the "SMTP authentication and relaying" section. It is possible your system has been "flagged" as being an open relay. If so, then you may be on many block lists.

To determine if your exchange server is an open relay, look here:

https://groups.google.com/forum/?hl=en#!topic/microsoft.public.exchange.clients/TfSIa7s0dk0