---
title: Mailbox Automapping
slug: mailbox-automapping
createdAt: 2025-12-07T23:54:30.739Z
---

Auto-mapping determines whether Outlook automatically adds an additional mailbox to a user’s profile when they are granted Full Access. Activate controls this behaviour through the mailbox rights applied to the mailbox and user. This document explains how auto-mapping works, how the DisableAutoMapping right influences behaviour, and the current differences between on-premises Exchange and Exchange Online.

# Mailbox Rights in Activate

Activate represents mailbox permissions using the MailboxRights flags. These describe all mailbox-related access that may be applied to a user or group:

- **Full** – grants Full Access to the mailbox. 
- **SendAs** – allows the user to send as the mailbox. 
- **SendOnBehalf** – allows the user to send on behalf of the mailbox. 
- **Forward** – configures the mailbox to forward messages. 
- **DisableAutoMapping** – indicates that Full Access should be applied without auto-mapping (supported on on-premises Exchange). 

Because these are flags, they can be combined. For example:

- Full + SendAs 
- Full + DisableAutoMapping 
- Full + SendAs + SendOnBehalf 

Activate interprets these rights and applies the required mailbox ACLs, AD security entries and mailbox attributes.

# Auto-Mapping Behaviour for On-Premises Exchange

Auto-mapping is an Exchange capability. Outlook automatically displays a mailbox when Exchange indicates that Full Access was granted with auto-mapping enabled.

Activate does not communicate with Outlook. It controls auto-mapping indirectly by specifying how Full Access is granted to the mailbox in Exchange.

## Full Access with Auto-Mapping Enabled

If MailboxRights includes **Full**, and does **not** include DisableAutoMapping:

- Full Access is granted to the mailbox. 
- Auto-mapping remains enabled. 
- Outlook automatically adds the mailbox to the user’s profile. 

This is the standard behaviour for most shared mailbox scenarios.

## Full Access with Auto-Mapping Disabled

If MailboxRights includes both:

- **Full**, and 
- **DisableAutoMapping** 

then on supported on-premises Exchange resources:

- Full Access is granted, but 
- Auto-mapping is explicitly disabled. 

Users retain Full Access but must manually add the mailbox to Outlook.

## DisableAutoMapping Without Full Access

If DisableAutoMapping is applied without Full, it has no effect. This flag only modifies the way Full Access is granted.

DisableAutoMapping is not a standalone right. It modifies Full Access and is ignored unless Full Access is being applied.

# Other Mailbox Rights

The following rights do not affect auto-mapping:

- **SendAs** relies on AD security permissions. 
- **SendOnBehalf** updates mailbox delegate attributes. 
- **Forward** updates forwarding attributes on the mailbox. 

These rights may be combined with Full Access with or without auto-mapping, depending on the service or workflow requirement.

# Example Scenarios (On-Premises Exchange)

## Mailbox Should Auto-Map

Use Full (and optionally SendAs or SendOnBehalf).
Auto-mapping is enabled and Outlook adds the mailbox automatically.

## Mailbox Should Not Auto-Map

Use Full + DisableAutoMapping.
Users still have Full Access but must manually add the mailbox to Outlook.

## Removing Full Access

If Full is removed from the rights set, Activate removes the mailbox’s Full Access entry, which also removes auto-mapping.

# Exchange Online Behaviour

Exchange Online does not currently interpret DisableAutoMapping in the same way as on-premises Exchange. The Exchange Online resource in Activate always grants Full Access using Exchange Online’s default behaviour.

## Current Limitation

- Full and Full + DisableAutoMapping both result in Full Access being applied. 
- Exchange Online’s default behaviour typically enables auto-mapping. 
- As a result, selecting DisableAutoMapping **does not suppress auto-mapping** in Exchange Online today. 

This is a known limitation of the current Exchange Online implementation and is on the Activate roadmap to align behaviour with on-premises Exchange.

## Impact in Customer Environments

- On-premises mailboxes behave as expected: DisableAutoMapping suppresses auto-mapping. 
- Exchange Online mailboxes do not currently honour this flag. 
- Customers who require Full Access without auto-mapping in Exchange Online will not achieve this solely by configuring DisableAutoMapping in Activate at present. 

# Summary

- Auto-mapping occurs when Full Access is granted with auto-mapping enabled in Exchange. 
- In on-premises Exchange, Activate correctly distinguishes between: 
  - Full → auto-mapping enabled 
  - Full + DisableAutoMapping → auto-mapping disabled 
- DisableAutoMapping only applies when Full Access is granted. 
- SendAs, SendOnBehalf and Forward are independent of auto-mapping. 
- Exchange Online does not yet honour DisableAutoMapping, but this alignment is planned.