Although I agree that if it’s a small business, it’s better to outsource it to an established business but if you’re serious about doing it yourself, check out OpenDesk/OpenCode. Also, why use your own hardware? A VPS is much more reliable.

Also, add 2FA

Biggest hurdle would be timing, if you want it sound right… Every speaker should be in sync as much as possible

Basically every serious mailserver package has imapsync included. I don’t know what kind of hardware you’re running and what you expect from the server doing the copying but running webmail, search indexes, antivirus, etc will cost you ram. There are solutions aimed at keeping backups of your mail though, I can’t give you recommendations, the only thing I remember is that they don’t give you a normal webmail or imap, instead you get a web-interface aimed at searching through the backup(s)

I adored my HP Veer, I bet that if I get a working one in my hands I’ll blind-type flawless again in seconds, I was better on that thing than any full size keyboard. Best phone I’ve ever had because of the keyboard and the ease of customization when you know Javascript. Screen was a bit too small (I consider every modern phone way, way too big) and speed could’ve been better but wasn’t bad.