Messaging Gateway

Mail is sent from Brightmail V8.0.1-7 with BATV enabled... The other end rejects with the error below.

Is this because Brightmail V 8 will not allow a null sender <> ??


FailureReason: 450 4.7.1 <recipiant@someotherdomain.at>... recipient denied, because MX 10 'my-relay.my-domain.com.' [xx.xx.xx.xx] for <prvs=24127cda86=undisclosed@mydomain.com> did not accept the empty address, <>, as required by RFC 821, 1123, 2505, and 2821

SMTPDSNDeliveryReason: ####################################################################
# THIS IS A WARNING ONLY. YOU DO NOT NEED TO RESEND YOUR MESSAGE. #
####################################################################

Your message could not be delivered for 1 days, 20 hours, 0 minutes.
It will be retried until it is 5 days, 0 hours, 0 minutes old.

For further assistance, please send mail to <postmaster>

If you do so, please include this problem report. You can
delete your own text from the attached returned message.

The Symantec Brightmail Gateway definitly accepts NULL senders as that is 'standard RFC procedure' for delivery of DSNs, including Non Delivery Reports.  I'm having difficulty understanding the 'roles' in your description.  Here's some information that may help you troubleshoot more:

1) BATV enabled will modify the sender of outbound SBG email to include the "prvs=" prefix. 
2) Should that email be bounced back to SBG, that sender turns into the recipient, and the the sender of the bounce is <>. 
3) SBG keys off of the NULL sender to to disect the "prvs=" recipient for validation purposes.

----

The text that you've shared is a delay notification.  i.e. The message is still in the queue, and can't be delivered.  It tends to suggest that the target MTA isn't accepting a NULL address. I would look to see if something might be subervting the BATV flow I've described above.

The delay turns into a fail after time has expired.

The relay that is not accepting the null sender is my inbound Brightmail box.