SMTP notifications sent by Enforce for either incident notifications or reports are not working. You may see in the Incident Snapshot -> History tab an entry that says "Notification Sent: Incident notification sent to null".
In the SymantecDLPManager log, you may find the following entries:
INFO | jvm 1 | 550 5.7.60 SMTP; Client does not have permissions to send as this sender
INFO | jvm 1 | DEBUG SMTP: got response code 550, with response: 550 5.7.60 SMTP; Client does not have permissions to send as this sender
The SMTP server may be configured so that accounts authenticating to the SMTP server can then only send e-mails using their assigned e-mail address as sender. If an account authenticates to the SMTP server and then tries to send an e-mail using an e-mail address which doesn't belong to that account, this is what the SMTP server will send in that SMTP response. As a result, the SMTP server blocks the mail send attempt.
In the case of the integration of Enforce-SMTP server, we are talking about the following two config parameters in Enforce's SMTP settings (located in the System | Settings | General menu):
The above error suggests that Enforce is configured in a way that the e-mail address defined in System Email does not belong to the account configured in User ID.
This should be fixed by either: