I've never used G-suite, so I can't say anything about it. But we use Email Detail Archive to backup all mailbox or selected emails as PDF files on the hard drives. This is a simple future-proof archiving solution - make PDF copies of your emails as you always know how to open a PDF. It's crucial as other archiving providers create custom files that you won't be able to open without additional software. Also, having the necessary info on your pc allows working even when there is no Internet connection.