EV 9.02 Exchange message export or recalls

I'm looking for advice on the best way to recall or export all Exchange email from EV 9.0.2.  We are planning to go from an on-premise Exchange 2010 system to Office 365 and need to recall or export everything from the Vault in preparation to putting things into the cloud.  As a side issue, we also have some EV archives which no longer have Exchange mailboxes that need exporting too.

Thanks for the help.