I have been unable to use that Email Import function in DT 3 to import mail from the desktop application, Microsoft Outlook. What results is it hangs / Beach Balls. All programs are updated to the latest version.
I will note too that each time I get to the Email Import window, status pops up that Plugin for Apple Mail is not installed or enabled. But it looks to be installed and enabled when I check Apple Mail.
Help? 
What version of DEVONthink are you running - 3.0.4?
If so, when the application is stalled, do a Spotlight search for Activity Monitor . Select DEVONthink in the list of processes - it should show “(Not Responding)” and the name in red - and press Command-Option-S to run a sample on it. When the sample window opens, press the Save button and save it to your Desktop.
Quit and relaunch DEVONthink, then hold the Option key and choose Help > Report Bug and attach this text file so we can inspect it. Thanks!
Thanks! I will do that. Do I attach it to this forum?
Also, I notice that the icon for Microsoft Outlook in the sidebar, when the icon is expanded no folders are listed.
No. Open the support ticket per my instructions.
Oh I see it now. Thanks! Also discovered a few more things that I’ll write in that support ticket. Thank you!
No problem