First scenario: Using Outlook 2016 under Win 7 that's connected to Exchange 2016:
If I have signed or encrypted mails in my postbox and wanna move them to another folder, it simply happens nothing. Independend if I use the ribbon menue, the context menue or simply try to move it by drag and drop. This happens with any folder: Either a "local" within my own exchange postbox, or a local pst where I archive my mails or the postbox of another exchange user.
Why I know it is connected with GpgOL / GPG4win: If I deactivate GpgOL I can move mails to any folder, no matter where the goal is.
Another hint: Sometimes (not 100% reproducable, but maybe it helps finding the reason) it works when I mark a not signed / encrypted mail and move the mail to its target folder without highlighting the mail I wanna move.
If I deactive the GpgOL option "automatically decrypt receipients key" it changes nothing, still I cannot move the mails.
To mention it explicitly: the is no error message, no hint why it cannot be moved. It simply happens nothing.
Same behavior I can reproduce with Outlook 2010 under Win 10 / GpgOL 2.1.1 / GPG4win with an IMAP account: If there is a signed or encrypted mail in my postbox I cannot move it to another folder (doesn't matter if another IMAP folder or a local folder in my PST) until I deactivate the AddIn GpgOL.
As descripbed above I sometimes can move mails if there is a non-pgp mail highlighted. So maybe there is an "exclusive access" to that mails by GpgOL so that they are prevented from any change like moving to another location.
I'm not a programmer but I hope the desciption is good enough for being understandable and helpful.