Thank-you everyone for voting.
The results were very interesting given the spread of the votes. However thunderbird is the clear winner here. Thus from today’s daily build - thunderbird will be the default mail client in 21.04 and geary has been removed as a default install.
Evolution. It looks great, has excellent mail, calendar and contacts integration with major providers, via online accounts, including exchange via evolution-ews, pst import plugins, and many more.
I will stay with evolution. But I fully understand, if people opt for Thunderbird because of multi-platform.