# How Synchronization Works

After configuration, Exchange Connector works automatically in the background and can keep data synchronized in both directions.

## Two-way synchronization

When a function is enabled, the connector can process changes from **vtenext to Exchange** and from **Exchange to vtenext**. Actual behavior depends on the enabled module, selected folder and configured mapping.

## How inbound changes are received

The mechanism differs between Exchange Server/EWS and Microsoft 365/Graph. Network requirements and the difference between EWS streaming and Graph push notifications are described in [Opening and Configuring Exchange Connector](https://manual.vtenext.ch/books/exchange-connector-vtenext-Hfx/page/opening-and-configuring-exchange-connector).

For provider-specific details, see [Configuring Microsoft 365](https://manual.vtenext.ch/books/exchange-connector-vtenext-Hfx/page/configuring-microsoft-365) or [Configuring Exchange Server](https://manual.vtenext.ch/books/exchange-connector-vtenext-Hfx/page/configuring-exchange-server).

## Synchronization is not always immediate

Changes are normally processed quickly, but a few minutes of delay can occur between the two systems. The connector also runs periodic checks to recover changes that were not processed on the first attempt.

If a change does not appear immediately, wait for the normal synchronization cycle before repeating the same operation.

## First connection

After connecting a new user or after a migration, the first alignment can take longer. Duration depends on the number of records and users, recurring events and connection speed.

## Avoid mass changes during initial alignment

During the first synchronization, avoid bulk imports, mapping changes, mass assignee changes and large Exchange folder moves. First verify that normal synchronization is stable.

## How to test

1. Create an easily identifiable test record in vtenext.
2. Verify that it appears in Exchange.
3. Modify it in Exchange.
4. Verify that the change returns to vtenext.

This is more reliable than testing with an old record whose previous history is unknown.