PST import when only journaling is used

Hello,

I used a third party tool to migrate data from a legacy archive (Mimosa NearPoint) into an Exchange  journaling mailbox that gets archived by EV 10.0.2. It is taking a very long time for EV to pull the archived messages out of Exchange, probably because of the poor format of some of the migrated messages. I was wondering if I create PSTs can I import them into the journal archive? Or does this only work with Mailbox archiving?

Thanks!