Hello -
I have a customer who I'm told formerly used Symantec's email security product, but has migrated to and uses Office365 - thus the Symantec product was dropped for them.
However, they have a business partner who does use Symantec Email Security. Their email system reports the email was successfully delivered, Symantec is reporting it delivered, but it is never making it to the Office365 service. The mail logs at Office365 do not see any attempt of delivery, rejection, etc of the mail from the remote domain. Microsoft confirms these findings.
I believe that the Symantec system is delivering the mail to the setup it sees for the customer in the Symantec system and is never actually delivering the email to the MX record.
I do not see any support option for this and the business partner has maintained that the issue is not on their end as it shows delivered.
What would my options be with getting this resolved (or at least ruled out) at Symantec?