That’s a bug of version DEVONthink Personal & Pro 2.9.7, the next maintenance release will fix this. One workaround is to restore version 2.9.6, another one to use the QuickLook panel by pressing the spacebar.
I recently decided to index all of my Outlook (for macOS) and Mail emails—which I regularly save to folders on disk as .eml files (and, in the past, when I used Outlook for Windows, as .msg files).
While DT 3.5 indexes both .msg and .eml files, when I try to view archived / indexed emails in DT, only .msg files actually preview. The .eml files show up as a blank window, with just the sender, subject line, and recipients showing at the top of the window, but with nothing from the body of the message displayed.
Is this a bug (alluded to in this, rather old, thread) that has reappeared, or is it a limitation of the version of DT that I’m running. I’m not sure if I’m running “Pro” or not and can’t figure out how to check—the about box doesn’t say anything about “Pro”.
The Standard edition doesn’t handle or index emails.
If you were using the Pro or Server editions, you could use View > Document Display > Text Alternative.