jrsilvey Some limitations/issues you cited about Mailspring were true at one point, but are outdated now.
Mailspring requires users to log in to the Mailspring Client
It is true that it required to create a Mailspring ID at one point to use it, but since version 1.9.0 released back in April, this is now optional, like you discovered for yourself.
It supports Exchange but needs IMAP enabled to work properly.
That is sadly still true. I tried setting up my Exchange university account to work with the Exchange protocol, but I had some issues. It does work flawlessly through IMAP, but I know that is not an alternative accessible to everyone.
It limits the amount of email accounts you can add to 1 or 2
I don't know where you got your information about that limit, but it used to be at 4 accounts for the free version, but it seems to be yet another restrictions they did away with earlier this year. Personally I have 4 accounts synced with Mailspring with no issues, using the free version. Even with over 10 accounts, you should be able to sync them all in.
It looks far better than Evolution.
Mailspring's Free version would give me (literally) everything I wanted in an email client.
I agree on both counts! Once I discovered Mailspring, I wasn't able to go back to other email clients!
Given what your issues were with Mailspring, I really think you should give it another try following the updates earlier this year 😉