We are having undeliverable message with the following error message "550 Error: Message content rejected" by sending email to one of customer as new message or replying our customer's email. However, We have no problem sending to others and that customer has no problem receiving from other that else. Any help would be appreciated. We are using Microsoft Exchange 5.5sp4 on NT4.0 sp6a.
Regards
naingtan
Regards
naingtan