I seem to remember Mail-in-a-box getting some support for running your own server. I've also seen kolabnow.com looking promising.
Duck Duck Go is my default search tool.
I mainly use Firefox as a browser and I use my work Outlook for calendar/contacts.
I know I can use more open source/portable tools but it's gotten me out of the Google bubble.
Unfortunately I can't get away from Android... and I like Apple's ethics less than Alphabet, so I'm stuck there.