Symantec Email Submission Client performs the following during the system update process:

Exchange notifications allow Symantec Email Submission Client to receive immediate notice of spam submissions. These submissions are processed immediately. Email Submission Client keeps track of spam submission mailboxes in a cache file that is stored locally on the server. The mailbox list that is obtained from Active Directory is compared with this cache file and only updates are made. New mailboxes get the spam submission folder added. Mailboxes no longer in the list have the spam submission folder removed.

The system update process is initiated in one of the following ways: