Our app user needs to run a stored proc that sends an email using sp_send_dbmail proc in msdb. I did add the user to the databasemailuser role and as a user in msdb. But if I attempt to execute the procedure with execute as user there is a deny on executing the stored procedure. If I execute as login it works. Everything I read says only the role membership is required, but I am implementing the certificate to sign the proc and attach to the user to see if this will resolve the issue. But I don't see anywhere that it says this is required if the user in the databasemailuser role so I am wondering if there is something else wrong. This is the first time I am setting up dbmail on SQL 2016 on Server 2016 so this is a little baffling to me as I have always gotten this to work on 2008. Thanks!