Yes to unified inbox, not sure about exchange but works well with IMAP

What you just described is called cooking.

External drive? Is it a usb drive? If it is you might be best pulling out the drive and connecting it to a sata port. The mount as read only and do what everyone else suggests

Did you know K-9 mail is soon to be thunderbird mobile

I went through this at the beginning of the year, it get 900/900 fibre, settled on openwrt running on a nanopi r4s. My other options were a nanopi r6s with openwrt, or nuc type hardware/server running something like pfsence/opnsence etc. The openwrt install took about 5mins then a couple of hours of exploring various menus options etc, which I didnt end up changing.

I looked at the nanopi r4s and the r6s when I replaced my router. I did consider doing it all myself but in the end settled on the r4s running opwenwrt, I think it took all of 5mins from download to working system. The benefit been the openwrt image has uboot included so only one image need writing, also web interface out of the box

Don’t think of it as an installation, it’s writing image files to disk. I prefer using gparted or disks when working with partitions. Then use dd for the actual writing as I can quite easily see I’ve got the right partition from gparted/disks. Got that wrong a couple of times 😅

I wonder if it’s the vegetable type or the viking type

Clearly not an arch user