I thought I posted about this earlier today, but the post hasn’t appeared here, yet. Perhaps I clicked on the wrong button somewhere.
In any case, I’ve been using the Clip-to-DevonThink add-on for Firefox and finding it useful. It would be convenient if I had a similar capability in Mail, i.e., to Clip-to-DevontThink from opened email messages. My sense is that capability does not exist now. If so, is it a possibility?
If you have installed the Apple Mail plugin (Help > Install Add-Ons > Apple Mail Plugin) then the “clipping” feature exists. In Mail, with a message selected, go to Message > Add to DEVONthink.
See also the “Importing from Apple Mail” topic in Help.