What is the best way to export bulk mailboxes out from EV ?

well, not 1 by 1...

If you set an attribute on the accounts, you can search on that attribute when exporting.

We used the State field, but you can also use Department or something you currently not use. Rightclick Archives in the VAC, select Export, To PST, you then get the dropdown and can see what you can use.

If you have 1 EV-server, it is simply setting a value like EXPORT.

Then select that field, fill in Export, select all, and export.

If you have mulitple EV servers, and the archives are on different servers, make the field look like EXPORTEVSRV01, EXPORTEVSRV02 etc. You can then export on mulitple servers at the time.

I have done 380 archives like this, took me a week.

Before you begin, you should define if the mailboxes need to be archived completely, or that you disable them for archiving, and then export the mailbox too. For archiving completely, check the QuadroTech site for the Archive Leavers tool... :-)