Email messages not being sent out for our Service Requests. This works for Incidents, Error in the Email logs shows:
System.Net.Mail.SmtpException: Mailbox unavailable. The Server response was: 5.7.1 Client does not have permissions to send as this sender as System.Net.Mail.MailCommand.....
It was determined that the Incidents email was being sent from the [email protected] address (example) but the Service Requests email was being sent from the [email protected] address.
The account that is configured to send outgoing emails in the Email Configuration is configured as [email protected]. This account should have "send as" rights to the [email protected] account in Exchange/AD.
**Note: Granting "full" rights did not resolve the issue, it needed to have the specific "send as" right enabled.
Once this was configured the emails from both the [email protected] and [email protected] addresses could be sent.