I have a customer with sbs2003 install and also Exchange is configured and is being used.
in the last few days i have noticed that i cannot email them and i get a bounce back 5.1.1
The specified user is on the system and has the address that is being emailed setup against them. it is now being mis-spelt either.
the Exchange server has 2x domains setup to receive on, one works and the other (the primary default) has stopped returning the 5.1.1 error to me.
I have successfully emailed the account (which fails when sending from my exchange server(this does send out successfully to other domains)) with a yahoo account.
so mine are not getting to the user from my excahnge server on my connection, but works from a webmail Yahoo account.
I have checked to see if my IP is blacklisted for what ever reason and it isn’t.
does anyone have any ideas? if just started happeing and i have checked the config on both servers and all seems to be ok.