Immediately after MaxExchange Server is started by launching MaxExchange Server Manager or rebooting the machine where the MaxExchange Service is installed, at least two packets are created for each remote and are saved in a folder called Upgrade (under the Outbox\[HEX Address Book ID] folder). Additional packets may be created as well depending on whether or not the server has additional transactions for the remote. The first packet contains information that sends a request to the remote for information added on the remote during the upgrade process. The second packet contains any other transactions, if applicable.

In mixed-mode environments (where the server and remotes are running different versions of MaxExchange), only updates and deletions from a remote that has not been upgraded yet are processed by the server. Additions are discarded until the remote upgrades. After a remote has upgraded, it sends a packet to the server and once that is processed, the packets in the Upgrade folder are sent to the remote and the Upgrade folder is deleted on the server. After the remote has processed the packet from the server, it creates a packet for the server containing information that was added on the remote during the time the mixed-mode environment was running.