I wish Mozilla would get into the email service market. I could really go for a reasonably-priced, ad-free, Gmail-sized, bring-your-own-domain email service.
... thunderbird? (I'm aware they're no longer maintaining it(?) but it's posed as a genuine option.)
Not only they're maintaining it again, but the number of developers assigned as been increased!
However, they intent the community picks its development up, eventually.
However, for now, thunderbird is being developed by Mozilla again, afaik
(i guess they understood there was the need for an e-mail client and that thunderbird was in a good place for competing.)
I, honestly, see KDE's Kontact as the ONLY decent OS alternative. Too bad it's not of easy install & support on windows... It would be a great e-mail client...