Trumps lawyers need to do a deep dive on all of Mueller’s hard drives to wipe the e-mails and all references to them.
Might provide some interesting reads of other files there....
The only legal way that Mueller could have obtained them is by formally requesting access or copies from the Trump Administraion. The White House lawyers would then review the email archive to scan for responsive documents and then vet the documents for privileged communications
Obtaining privileged Presidential transition documents the way it was done is an explicit clandestine end run around proper constitutional executive privileges and also constitutional separation of powers.
The Mueller investigators handling these documents are partisan hacks who do not have proper security clearances to view the documents and a number of these emails have already been illegally leaked to the media by said partisan hacks.
It's a 100% certainty that they have been given to Democrat opposition research operatives.
What Mueller has done is illegal and unethical as hell.
You can get a subpoena for responsive documents from an email archive, but you can't just obtain a data dump of Presidential transition documents that contain informationtnah covered by Executive privilege and Attorney-Client privilege
If Rosenstein approved this illegal fishing expedition his career is over and he deserves prosecution. I suspect that he did