I always found evolution to fit my needs best as outlook replacement. You also need the packet evolution-ews (Exchange Web Services) when using with Exchange server.

Well, if the CMOS battery is dead, you'd usually see a warning when starting the PC that default values are loaded. And of course the time settings wouldn't be preserved. You can check that if you set the time in BIOS or OS, switch off the PC and disconnect your power source. let it sit some time, give it power again and turn it on. If the date & time is lost, it's the battery. But these batteries are pretty durable, they easily last around 10 years in my experience... I've had more trouble with HP SAS controller batteries in servers, they seem to have a much shorter lifespan.

I have devuan ascii running on an Intel NUC5i3RYK with M.2 Crucial MX200 500GB. No problems here. Installer found it all by itself, I chose to give devuan the full disk and on it went.

Edit: I used the DVD installer and not the minimal.iso...