How Synchronization Works

How does Outlook-Android Sync compare and synchronize?

Outlook-Android Sync compares data from Outlook/Office 365/Exchange Server and Android and if some of the items are found to be similar to those that are already present on either of the sides but with older "last change" date, they will be overwritten by newer items. When overwriting items, Outlook-Android Sync will consider the old ones obsolete and delete them. If new items are found on one side, they will be considered as new and copied over to the other side.

All synchronizations are bi-directional and always happen in both directions unless chosen otherwise in options.