While researching the ways to remove the "email invalids" from my database, I saw a discussion asking how to remove the email address for those leads that are marked "email invalid." I have a solution, but can't find the discussion string, so here's the answer:
1. In "Marketing Activities" tab, create a smartlist with: Email Invalid = True
2. Go to the leads tab and choose the "select all" button at the top (below the "Smartlist" tab).
3. Click the "lead Action" button and choose "marketing activities" then "change data value."
4. In the "Attribute" box, search and choose "email address"
5. Next to "New Value" type NULL (in all caps).
This will blank out the field for all selected leads.
I'm also setting up a trigger campaign that automatically unchecks the "email Invalid" box once the email address is updated.