Got an email problem to throw at you --
User tries to send email to firstname.lastname@example.org that forwards email to email@example.com, but it bounces back like so:
The following recipient(s) could not be reached:
firstname.lastname@example.org on 3/6/2006 9:34 AM
There was a SMTP communication problem with the recipient's email server. Please contact your system administrator.
<exchangeserver.domain.com #5.5.0 smtp;554 <email@example.com>: Relay access denied>
Googling the 554 error, everything I've thus far read said it's a problem with the sender's SMTP settings. However, this user can send email to anyone else, just not this particular user.
I checked the settings on the server that handles email forwarding, and all that's configured as it should be -- firstname.lastname@example.org is indeed configured to pass email along to email@example.com.