Mailbox Automapping
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.