Being a long time user of former Ksnapshot (now KDE-spectacle), I would have rated it 5/5 if it were on a Plasma desktop... But the issue with Cinnamon has always been that feature "capture a region" does not work. Worse, it's impossible afterwards to get back to the Cinnamon desktop!"
What do you think?
Now that you mention it, that’s the reason I have Spectacle and Shutter installed because Spectacle doesn’t work right in Cinnamon.
As far as Kontact/Kmail, it always had issues the last time I used it. Probably best to stay away. I think I mentioned it mostly because it would be an awesome suite if it worked and it’s been a few years since I used it.
Thunderbird, plus that Lightning extension if you want a calendar and then maybe a theme. Made by Mozilla but closest to outlook for linux/ubuntu?
I used outlook for years.
Search for ‘email client’ in Software Manager/Center. Whatever it lists should be compatible. Synaptic, another software center type program, tends to show more but not all are completely compatible sometimes.
I did see another one that I hadn’t seen before, Claws Mail.
Looks pretty decent. I might try it sometime because I agree with you as far as firefox/mozilla goes.