I have Exchange 2003 set up with Symantec Premium AntiSpam on Server 2003. I have a user that received an email from outside our network that went to multiple people. The person who sent the first email sent it from her company with no problems. When that same person tries to respond to everyone again on the email thread from her Blackberry, it gets bounced back from my server with the following message: From: "Mail Delivery System" <MAILER-DAEMON@smtp03.bis.na.blackberry.com> Date: 04 Jun 2008 18:06:36 ToRS0=VCXmGC=WS=companyx.org=user@srs.bis.na.blackberry.com Subject: Delivery Status Notification (Failure) The following message to <user@companyz.org> was undeliverable. The reason for the problem: 5.1.0 - Unknown address error 550-'5.7.1 Requested action not taken: message refused' He can still receive replies on the same email from other Exchange servers. It only happens from the Blackberry. I have added the origianl email address from companyx and the blackberry address to the white list in Symantec so it should go through. Any ideas on what I am missing on my Exchange setup that is blocking this? I currently have the Intelligent Message Filtering set to 9 with No Action when it receives SPAM. Thanks. Robert

We have the same problem, even though we don't have any Symantec product installed. This seems related to Exchange and SPF, although I'm not sure. Anyone found a solution?

I'm getting the same error on my Exchange 2003 server: Reporting-MTA: dns; smtp03.bis.na.blackberry.com Diagnostic-Code: smtp; 5.1.0 - Unknown address error 550-'5.7.1 Requested action not taken: message refused' (delivery attempts: 0) I will try and add the sender to the Exchange safe list. :s