In Exchange 2007 / 2010 / 2013, VIPRE Email Security uses Impersonation to quarantine spam and check the contents of a user's Allowed/Blocked Senders Folders & Contact list. 

If this feature is not configured correctly, issues such as scored spam messages being delivered to inboxes can occur.

Testing Microsoft Exchange's Impersonation: 

Note: The following is to be performed on Exchange's Hub-Transport Server

  1. Open a Web Browser (Internet Explorer, Firefox, Chrome, etc.)
  2. Navigate to Exchange's OWA Website for a user receiving Spam:
    • Example: ExchangeServerName / owa / User@Domain.com
  3. At the login page, enter the Impersonation Account's credentials
If the login is successful and the User Account can be modified, Impersonation should be working.

If the login fails, run through the following article and attempt the process again:

VIPRE Email Security's Impersonation attempts fail