The item count for the offline folder depends on the Mail to keep offline or the Download email for the past setting. Right-click an offline folder, and select Properties. Determine whether offline folders are being synchronized This article provides guidance to troubleshoot and resolve these issues. ost file or the Exchange Server support file is damaged. When you try to synchronize a Microsoft Exchange Server mailbox with an Offline Outlook Data File (.ost), the synchronization fails, and you experience any of the following issues:
Applies to: Outlook 2019, Outlook 2016, Outlook 2013, Outlook for Microsoft 365.
Issues when you synchronize your Exchange Server mailbox with your.
