A business (multi million dollar business.....) didn't want to spend the money to get proper business class email.
Microsoft exchange eliminates all that. You can enable and use the archive mailbox after you hit the 100GB, up to 1.5TB
I'd lean on the archive mailbox feature of the Business 365 ecosystem.
If you are on the Biz 365 space and using Exchange 365, I'd just leverage the built in mechanisms. My personal opinion.