This is an error returned by the downstream Microsoft Exchange Server. It occurs because the Exchange Server is either unavailable or has low disk space which should be freed.
To resolve the issue, please contact Microsoft support.
Interscan Messaging Security Virtual Appliance9.0 , Interscan Messaging Security Virtual Appliance8.5
IMSS does not deliver any mails to the Exchange Server. For each email, you will see the following entry in the message tracking of the console:
452 4.3.1 Insufficient system resources\r\n
This is an error returned by the downstream Microsoft Exchange Server. It occurs because the Exchange Server is either unavailable or has low disk space which should be freed.
To resolve the issue, please contact Microsoft support.
