Just noticed thunderbird 91.2.0-1.el8.plus is not available in the "plus" repo for CentOS 8. It does exist for CentOS 7. The plus release keeps encrypted email functional in the new 91.x ESR release by not removing a library RHEL doesn't want to ship/support. If there are other workarounds/things to install to make the non-plus version work, I would appreciate the info. Thanks!