When using the term “Exchange Mailbox”, we are using an “alias” for a Database that hosted on the Exchange server.We can describe the OWA (Outlook Web Application) mail client as a “viewer” for the data that stored in the Exchange database, and the Outlook mail client as a “viewer” for the database (OST File) that stored on the user desktop (Hard drive). WAN environment: When using a local Exchange Server (on-premises), Outlook synchronizes data to and from the Exchange Mailbox, by using a local LAN infrastructure. I am getting basically the inverse, now: all folders, and the messages within them, have downloaded. A new, test message I sent downloaded correctly and appears in my Inbox, but none of the existing messages in the Inbox did.
For Outlook 2013, Exchange accounts can sync as little as 1 month, while Outlook 2016 can sync as little as 3 days of messages.Groups received a lot of attention from Microsoft at the recent Ignite conference in Chicago.Positioned as a single identity that enables group members to access resources drawn from across Office 365, these groups are also regarded as a potential migration path for traditional Exchange resources such as distribution groups and public folders.Using a local copy of the Mailbox content should significantly improve the Outlook performance (response time) because access to the “data” (Mail items) created by using a local copy of the Mailbox that stored on the local drive.Instead of “fetching” the mail from the remote Mailbox, each time a user click on the mail item.So, in case that this is your scenario, the only advice that I can offer is: Be patient and read the information 🙂 By default, Outlook client is configured with the option of cache mode.