SWMBO now has so many unread emails that she is now paying Google for extra storage space. 15 gigabytes isn't enough.

She currently has more than 20,000 unread emails, more than 17,000 in her in-box alone, going back as much as five or six years. There is absolutely zero chance that she will ever look at any email more than a month or two old.

I would like to arbitrarily delete everything in her in-box that is more than three months old. The best I have been able to do is delete them one screenful (i.e., 100 emails) at a time. Is there a better way?

tanstaafl.