Just a heads up … Apple yet again changed Apple Mail somehow or another with the most recent update to 13.3.1 making the the two Mail Plug-ins I use, one of which is for DEVONthink, “incompatible” with Apple Mail.
For DEVONthink, easily fixed by Menu: DEVONthink → Install Add-ins → and click “on” to install the Apple Mail Plug-in Version 4.0.9).