Backups - Restore - Archiving From Gmail?

Does anyone know once all the emails are downloaded from Gmail via IMAP and backed up if this is a stand-alone backup of emails and attachments?

MY GOAL:
I’m trying to archive ALL Gmail, and nix my online Gmail messages … then use emClient as POP - _ I just wanted to be SURE I actually have a copy of everything in the emClient backup? _

My worry is it’s only an imap copy of headers and not the actual DATA, which in my case is almost a Terabyte?

THANKS FOR ANYONE’S HELP! :slight_smile: