Yes: I loved the eM Client.
No: Every day a different disruption. Currently I cannot open signed pdf files.
This is not possible at all. eM Client v8 - farewell. I will not go back the way I came. The community is screaming - the development is silent.
I am back to Firefox 78.1.0.
Backup my e-mails again with mailstore home.
CardBook- and TbSync- AddOn work clean in the first run.