TenantPilotGet TenantPilot ↗
← All Microsoft 365 guidesSHARED MAILBOXES · EXCHANGE ONLINE

Shared mailbox Full Access vs Send As: what’s the difference?

When someone needs to help with a shared mailbox such as [email protected], there are two permissions you are likely to encounter: Full Access and Send As. They solve different problems—and one does not automatically include the other.

Microsoft 365 admin guide · Using fictional example accounts · Updated October 2026

Full Access vs Send As at a glance

Full Access

Open the shared mailbox, read and manage its contents. It does not grant permission to send as that mailbox.

Send As

Send email that appears to come directly from the shared mailbox. It does not grant access to read the mailbox.

You may need to grant both permissions for someone to read and respond to mail using the shared address. A separate Send on Behalf permission identifies the sender as acting on behalf of the mailbox, which is not the same as Send As.

Before you assign access

  • Confirm approval from the mailbox owner or your organisation’s authorised process.
  • Check that the selected user and mailbox belong to the correct Microsoft 365 tenant.
  • Grant only the access the person needs, and record why it was granted.

Option 1: Use the Exchange admin centre

  1. Go to Recipients → Mailboxes and select the shared mailbox.
  2. Open Mailbox delegation.
  3. Choose Read and manage (Full Access) or Send as and add the authorised user.
  4. Save and verify that the user is listed under the intended permission type.

Option 2: Use Exchange Online PowerShell

To give a colleague Full Access:

Add-MailboxPermission -Identity "[email protected]" -User "[email protected]" -AccessRights FullAccess -InheritanceType All

To grant Send As separately:

Add-RecipientPermission -Identity "[email protected]" -Trustee "[email protected]" -AccessRights SendAs

Verify the result:

Get-MailboxPermission -Identity "[email protected]" -User "[email protected]"
Get-RecipientPermission -Identity "[email protected]" -Trustee "[email protected]"

Access changes can take time to become visible in Outlook. The commands above use fictional addresses and assume you have connected to Exchange Online with suitable permissions.

How TenantPilot helps

TenantPilot provides suitable Full Access and Send As mailbox tasks. Rather than remembering the command and parameters, an authorised user can choose the task, check the mailbox and colleague, and review the action before execution.

Common questions

Does Full Access include Send As?

No. These are separately assigned permissions.

Will a shared mailbox automatically appear in Outlook?

With individual Full Access assignments, Outlook may automatically add it through auto-mapping, depending on the mailbox and client configuration. This is not always immediate.

Should every member of staff have access?

No. Use your organisation’s approval process and give each person only the access necessary for their role.

Microsoft documentation

Microsoft 365 interfaces and PowerShell modules may change over time. Check the linked Microsoft guidance for the latest instructions.

Prefer a guided way to handle everyday tasks?

TenantPilot is a Windows app designed to help authorised staff complete suitable Microsoft 365 admin changes. It complements your existing IT support partner, including when a routine task cannot wait.

See TenantPilot in Microsoft Store ↗

TenantPilot does not replace IT support or your organisation’s approval and incident processes.