We use a database that was developed inhouse as an email approval system. The database uses a lookup mechanism to pull in group names that are also housed within the same database.
The code then populates the bcc field with the recipients names pulled from the groups. The SendTo and cc fields are empty.
This has worked well for sometime now.
We have also begun to migrate users to Outlook for their email client. The new Outlook users are failing to recieve these emails.
Perhaps you were just using shorthand, but just to be clear, precisely what is the name of the bcc field? Is it “BlindCopyTo”? I assume it is because I don’t believe it would have worked before otherwise.