Since I upgraded to Yosemite with mail 8.0 I discovered some weird behaviour:
- messages can only be dragged from the INBOX into a group in DTPO
- messages from other mailboxes like Sent etc. can not be dragged/dropped into a group in DTPO
- attachements in messages dragged from the INBOX into DTPO are empty
- messages imported via Message>Add to DTPO works fine but is no substitute for drag/drop because im filing a lot of e-mail directly into DTPO groups
Under Mavericks everything worked without a flaw.