Every arrow below is something the software actually does today, on two live servers and 26 mailboxes.
Crazydomains, Gmail, Microsoft 365 or your own mail server. This stays exactly as it is. Staff keep their same address.
A second copy of every message and attachment, scrambled on the disk. It can sit on a machine in your own office, or on ours.
Set up once, then it behaves like any normal mailbox.
Any browser, no setup. Read, search, download.
The mirror is copied again to another machine. Every night we read real files back out of that copy and compare them, and the result shows on your dashboard the next morning.
What it does not do.