Upgrading GW7 post office on an NBO server

[gleach1]

Hi all,
Have found a couple of threads on this but not much else, we have an NBO server running 7.02 with the primary server running 7.03. We have 1 user in GMS that is having issues and their mailbox is on the NBO server.

Since 7.02 has known issues with GMS, are we able to upgrade this PO to 7.03 safely? I'm not 100% sure of the NBO version in use, it's 2.x something