Excluding User(s) From IMF in Exchange

Exchange 2003 SP2 offers a new feature called Intelligent Message Filter which provides Spam protection for users with mailboxes on the Exchange server. There are some cases when you may have a user, or users who do not wish to have their mail filtered and rely on other methods for Spam prevention.

You have to install a Hot Fix KB912587, This is an unsupported hot fix that has not passed regression testing, and so make sure you test it before you deploy this in your production environment.

With the hot fix installed, there are a few registry settings you need to configure. Open up the registry for editing and drill down too

HKEY_LOCAL_MACHINE\Software\Microsoft\Exchange

Create a new key called ContentFilter and under this create a new DWORD called CheckRecipients. You have two options for IMF exclusion

- Inclusive - Setting the value of CheckRecipients to 1 will cause the IMF filter to be bypassed as long as one recipient is on the list of recipients.
If an email is sent to 10 people in the organization, and one of those users is excluded from IMF, the message will not be filtered for anyone.
- Exclusive - Setting the value of CheckRecipients to 2 will cause the IMF filter to be bypassed only is all recipients are on the list. If an email is sent to 10 people in the organization, all the recipients must be excluded from IMF for the message to pass through unfiltered. If even one user is not on the list the message will pass through IMF.

Finally you need to create a new Multi-String called RecipList and enter the SMTP address of the recipients you want to exclude from IMF.