550 permanent failure processed as Soft Bounce

[Alpha1]

Affected version

2.3.7

This bounce message is incorrectly processed as a Soft Bounce:

Action: failed
Final-Recipient: rfc822; xxx@evansinc.com
Diagnostic-Code: smtp; 550 permanent failure for one or more recipients (xxx@evansinc.com:550 5.4.1 Recipient address rejected: Access denied. For more information see https://aka.ms/EX...)
Status: 5.3.0

This clearly should be treated as a hard bounce.

 

[Alpha1]

Similar status messages:

Action: failed
Final-Recipient: rfc822; xxx@dtcc.edu
Diagnostic-Code: smtp; 550 5.4.1 Recipient address rejected: Access denied. For more information see https://aka.ms/EXOSmtpErrors [BL02EPF0002992E.namprd02.prod.outlook.com 2025-11-05T10:00:32.317Z 08DE1927D5E0CE41]
Status: 5.4.1

Action: failed
Final-Recipient: rfc822; xxx@lecter.org
Diagnostic-Code: smtp; 550 No such recipient here
Status: 5.3.0