Hi,
The plugin Mail is not installed in this version.
thanks
2016-02-23_16-08-08.tiff (814 KB)
For some time, Apple has “kicked out” installed plugins in Mail with each update or upgrade of OS X.
Run the Install Add-Ons routine once more to reinstall the Mail plugin. (To find that routine, click on the DEVONthink application name in the menubar, then choose Install Add-Ons.)
PS: You are running beta software and shouldn’t expect things to behave like the public release.