it seems to be impossible to select and copy text from imported e-mail messages. Also, it seems strange that if I select a message, the contextual menu item Open with says Mail is default, but when I use the menu item Open… a new DTP window is opened with the message.
DEVONthink 2.0 displays email messages using QuickLook and the QuickLook preview for .eml files does not permit copy and paste. But you can switch to the text only view via the navigation bar (above the preview itself) and copy from there.
Mail is default as an external application but the Open contextual menu command will always open it internally.
I didn’t see where the original poster indicated which version of DT (s)he is using, but I wanted to point out that the above feature is only available with DTP Office. There currently is no way in DTP 2 to switch the display of emails to/from Quick Look and text view.
I use DTP Office 2.
The Open command is intended to open a document within the database environment, if possible.
The Open With command is intended to open a document under an external application, if possible.
Example: DEVONthink is capable of opening and viewing a PDF document within the database. When Open is invoked, the document will be opened in its own window, still inside the database environment.
When that same PDF is selected and Open With is invoked, the user will be offered a choice among other applications on the computer that can open the PDF outside of the database environment. If the Default application, Preview is selected, the PDF will open under Preview.
Note: The Open command in DEVONthink 1.x was available only for those documents that could be opened within the database as plain or rich text, HTML (including WebArchive), PDF/Postscript, images and QuickTime media. DEVONthink 2.0 adds documents that can be displayed within the database environment using Quick Look.