Is it possible to disable the ability to perform the “unmatch” function?
Yes, there a few options you may take for this feature to happen. See Details.
Prohibiting Users from using the Unmatch feature can be accomplished in different ways, depending on exact work flow desired.
The buttons Match/Unmatch/Delete are available on the Email Messages object when displaying the Visualforce view. It is not possible to change these buttons in this view. It is possible to employ Match My Email’s related list to display Email Messages. While the related list does not offer the hover over subject or the right column showing related matches, it does allow you to control which buttons are available. One would go to an object such as a Contact and edit the Page Layout. For the relate list of Email Messages, click the wrench icon to open properties and click the + to expand Buttons at bottom. Here one can choose which buttons to make available.
If a User is viewing email in the Match My Email Email Cloud, they can hover over the phrasing in the Type Matches column, either No Match or Match info, and choose Unmatch in pop up window. This cannot be disabled. An End User can only see his own email in Email Cloud and would only be able to Unmatch his own imported copy of an email message. If by unmatching, it results in a No Match state for the email, it will automatically be reprocessed by our system at next cycle and re-matched. However, if after unmatching to a particular record there are still matches in place, no automatic reprocess would occur.
For assistance or questions, please contact email@example.com.