My mother-in-law has been using Outlook for 10+ years and is having all kinds of issues with a very large .pst file. She currently uses it with POP based email provider only (she is an individual and no Exchange server is in the mix). Her .pst is over 7GB.
Once we can get her email archive into the Google cloud, she would stop using her POP provider and exclusively use Gmail. She already has a Gmail account (not apps).
It is important for her to preserve her folder structure as well as her attachments.
Outlook 2007 is painful to use with IMAP, so would prefer to not use that option if we don't have to.
I've googled this and most of what I've seen is very old and not current.
What is the best way to do this?