I agree. There seem to be many valid leads that chose to use their gmail.com accounts I would love to add gmail.com to the whitelist free domain emails I would accept.
You have the choice of all or nothing. Or you can enter the domains you want to block with a comma after each. But there are hundreds. It would be SO nice to have a list where you can select all, and then deselect the few you wish not to block. PLEASE add this feature!