We are using here Exchange 2003 STD, with a Barracuda SPAM/Spyware Firewall 400.
When a user leave the organiztion, usually delete the account, backup and flush the mailbox and then delete exchange attribute and purge the mailbox.
However, if a client send an email to a user that left, the email does not bounce. the sender never receive anything that tells him that this email is not valid.
did someone know why ?