# Editing a Mapping

Custom mapping changes are available for **Contacts** and **Organizations**.

<div id="bkmrk-before-you-beginsave" style="background:#fff4cc;border-left:5px solid #d39e00;padding:14px 16px;margin:16px 0;color:#4a3b00;">**Before you begin**  
Save a screenshot of the current mapping and review [What Happens When a Mapping Is Changed](https://manual.vtenext.ch/books/exchange-connector-vtenext-Hfx/page/what-happens-when-a-mapping-is-changed).</div>## Procedure

1. Open **Settings &gt; Exchange Field Mapping**.
2. Select **Contacts** or **Organizations**.
3. Click **Edit**.
4. For each row, select the corresponding Exchange and vtenext fields.
5. Use **Add mapping** when another association is needed.
6. Review all rows.
7. Click **Save** and confirm the warning.

[![Editing Exchange Field Mapping](https://manual.vtenext.ch/uploads/images/gallery/2026-09/scaled-1680-/eQadauIoHiKeg6AM-immagine.png)](https://manual.vtenext.ch/uploads/images/gallery/2026-09/eQadauIoHiKeg6AM-immagine.png)

## Mapping rules

### Compatible field types

An Exchange field can only be associated with a compatible vtenext field type.

### A field cannot be used twice

The same Exchange or vtenext field cannot be reused in two different mappings.

### Main e-mail is mandatory

Contacts and Organizations must include a mapping for the Exchange **Primary E-mail** field (`EMAIL_ADDRESS_1`). Saving is blocked if this mapping is missing.

### Locked fields

Rows shown as locked cannot be edited.

## Using --None--

When a field pair should not be synchronized, it can be left on **--None--**.

## Before clicking Save

<div id="bkmrk-operation-with-impac" style="background:#fde8e8;border-left:5px solid #b42318;padding:14px 16px;margin:16px 0;color:#7a1b14;">**Operation with impact on synchronized data**  
**Save** does more than change the configuration: for Contacts and Organizations it can trigger a rebuild of Exchange synchronization. Read the next page before changing a production system.</div>