tellmail lookup command and surgewall

I have several domains that we “surgewall̶1; to help reduce spam, viruses, etc. However, over the years, there are thousands of accounts that were created by surgewall. We wish to remove those accounts that have not been used for more than six months. How do I do this? When I run tellmail lookup on a valid account surgewall created account, that gets activity on a daily basis, it shows it as “Account not used”; – which is incorrect.

 

How do I determine which surgewall created accounts have not had any mail in the last six months?

 

----

Dan Troxel