A couple of my users are getting an bounce when sending messages to some people. It seems random as they have been able to send other messages to the same recipient and other users are able to send the same message to the same recipients. (If that makes sense)
The NDR is
There was a SMTP communication problem with the recipient's email server.
5.5.0 smtp;501 Rewrite failure, please try again later
I'm guessing this is a temp glitch at the time of sending (rather than config problem) but as I can't find any info on this particular message, I'm at a loss. If somebody can shed some light on this problem or point me in the direction of some information, it would be greatly appreciated.
Exchange 2003 6.5.7651.61 SP2
Windows 2003 R2 Std Edition SP2
We use McAfee Enterprise v8.7.0i
And Clearformat email branding, with Postini filtering behind them.