The Exchange Best Practices Analyzer is a great tool to check your Exchange setup. You get a lot of excellent guidance about various aspects of Exchange, presented as items of different severity. In the results list of a scan you can select to hide items that you do not want to be alerted about the next time the tool is run. A couple of times I have pressed the wrong choice in that list and subsequently hidden items I wanted to investigate. I could not find a UI to recover those hidden items and that prompted me to try to find out by myself. Turned out it was very easy.

The items you have suppressed are stored in the registry. The path is:

HKCUSoftwareMicrosoftExchangeExBPA

The key is called SuppressionData and has a string data type. All the items you have suppressed are listed in this key and you can recover them by deleting individual ones or all of them. The values are comma separated.

Here is a sample of the data in SuppressionData (data modified for readability):

C:>reg query HKCUSoftwaremicrosoftexchangeexbpa /v SuppressionData

HKEY_CURRENT_USERSoftwaremicrosoftexchangeexbpa
SuppressionData
REG_SZ
fDisclaimerWithoutException,fMaxMsgOutgoingNotSetOrganizationTEST-ORG

In the ExBPA you can select to hide an item for a particular instance or for all instances. The choices in the UI are “Do not show me this item again for this instance only” and “Do not show me this item again for all instances” respectively. Which choice you make is reflected in the registry by appending the name of the instance you were working with to the name of the item. In the above sample the fDisclaimerWithoutException value will hide the disclaimer exception item for all instances, while the fMaxMsgOutgoingNotSet item is hidden only for the TEST-ORG organization.

After you have manipulated the SuppressionData value in the registry you have to restart ExBPA for the changes to take effect.