Dug further and found this error:

The server principal "xxxx" is not able to access the database "yyyy" under the current security context.

Where xxxx is the SQL Server Agent account. Added...

Changed both server and agent to run as Network Service. Same results. Changed both server and agent to run under same network account name & password. Same results.

Thank you.

This post was a reply to your post:

Maybe - when email is sent successfully from management studio the last_mod_user entry in sysmail_log is NT AUTHORITY\NETWORK SERVICE and when it fails...

Maybe - when email is sent successfully from management studio the last_mod_user entry in sysmail_log is NT AUTHORITY\NETWORK SERVICE and when it fails after invoking sql agent job that entry...

the sproc executes fine & sends the email with the attachment when called from management studio so I would say the sproc and the call to sp_send_dbmail within it are...

and BTW - when the sproc is executed from management studio & not called as sql server agent job, it works. Weird.

Tried both suggestions, first @append_query_error = 1, same result. Then changed file name to @query_attachment_filename = NULL and got the error message added twice to sysmail_log after executing the job....

All latest patches have been applied. This is a fresh vm just put online in the last 2-3 weeks. All other services are working with no issues.

Thanks for your effort! No, it is the opposite. It has been working flawlessly for years with the same setup on 2005. We are migrating to 2008 (finally) and we...

All emails come from the same email address and there is only 1 profile each set up on the 2005 and 2008 machines. Anonymous authentication is used in the Database...

Thank you for your reply. If that is the issue then it is somewhat mystifying because the same exchange server currently receives the email from Database Mail on SQL Server...