I was up to 87% full in Gmail, but there was no way I was going to search for every e-mail that had an attachment (type “has:attachment” in the search box), because I couldn’t sort by size. So I could spend hours deleting e-mails and gain only 1% back. I did search for “filename:.mov” to get rid of one kind of file that I knew was big. Even that would take forever, so I cast about for another way.
I finally found it: use Outlook to download headers only, then sort by message file size, then delete messages in Outlook, then sync up again. Would you look at me now!
Full instructions here.
I’ve used this and found it quite helpful:
http://lifehacker.com/5662849/find-big-mail-sorts-your-gmail-attachments-by-size-for-easy-clean+outs
Good tip, Dustin! I just tried that, and it’s a great approach that can either replace or complement the one I mention.