Replacement for Thunderbird?

[gordol]

I have Thunderbird installed on two Win10 computers, a desktop and a 2-in-1 laptop. Both machines have Win10 as factory installs (ie, not upgraded from a prior OS). Thunderbird on the desktop works pretty well, but I am having constant database issues on the laptop.

I have tried to fix this by using the built-in database repair tools, and also by completely wiping the profile folders and copying the profile folders from my desktop computer. TBird was shut down for this. No change.

TBird on the desktop runs 24/7 for primary spam filtering, to keep it off my phone. TBird on the laptop runs when I'm at work, or occasionally at other times.

Considering that TBird is also no longer in development other than critical security fixes, I am looking for a replacement and am looking for suggestions. I do have some non-negotiable feature requirements, plugins to add the functionality is acceptable:

Support at least two email addresses / servers
Support actual syncing of Google Contacts
Bayesian (adaptive / learning) spam filters
Manual filing rules
IMAP, SMTP with SSL/TLS

Would-be-nice includes unified Inbox

I've already looked at eM Client, Windows Mail, Outlook 2016, and Mailbird.

eM fails on spam filtering, and has no way to treat individual messages in a thread as individual messages without turning off the Conversation View

Windows Mail fails on spam filtering
Mailbird fails on spam filtering
Outlook fails on spam filtering and Google Contacts. The only add-on I'm aware of for Google Contacts with Outlook does not work with newer than 2010.

I had previously tried The Bat, but I do not recall why I rejected it, and now cannot re-test due to their trialware restrictions.

Alternately, if there is something I can do to fix TBird on the laptop, I will happily stay with it.