This error is encountered when attempting to send email from Blackbaud NetCommunity after an upgrade has been performed.
1.) Access from the BBNC WS Server "C:\Program Files\Blackbaud\bbappfx\MSBuild\bbAppFx.Config.exe"
2.) Select on the left hand side "AddApplicationUser"
3.) Ensure that the Server name and Database name are correct for your environment
4.) "IsSysAdmin" is set to "True"
5.) Input "NT AUTHORITY\SYSTEM" as the user
6.) Select "Go"
***Note***Once the user has been added to the database simply copy any failed email message in BBNC and resend the copied message. Any messages that have failed out with the above exception will not be sent even after adding the user.***