Understanding Outlook add-in permissions

Outlook add-ins specify the required permission level in their manifest. There are four available levels.

Permission level canonical name	XML manifest name	unified Microsoft 365 manifest name	Summary description
restricted	Restricted	MailboxItem.Restricted.User	Allows use of entities, but not regular expressions.
read item	ReadItem	MailboxItem.Read.User	In addition to what is allowed in restricted, it allows: regular expressions Outlook add-in API read access getting the item properties and the callback token writing custom properties
read/write item	ReadWriteItem	MailboxItem.ReadWrite.User	In addition to what is allowed in read item, it allows: full Outlook add-in API access except makeEwsRequestAsync setting the item properties
read/write mailbox	ReadWriteMailbox	Mailbox.ReadWrite.User	In addition to what is allowed in read/write item, it allows: creating, reading, writing items and folders sending items calling makeEwsRequestAsync

Permissions are declared in the manifest. The markup varies depending on the type of manifest.

• XML manifest: Use the <Permissions> element.
• Unified Microsoft 365 manifest (preview): Use the "name" property of an object in the "authorization.permissions.resourceSpecific" array.

Note

• There is a supplementary permission needed for add-ins that use the append-on-send feature. With the XML manifest, you specify the permission in the ExtendedPermissions element. For details, see Implement append-on-send in your Outlook add-in. With the unified manifest (preview), you specify this permission with the name Mailbox.AppendOnSend.User in an additional object in the "authorization.permissions.resourceSpecific" array.
• There is a supplementary permission needed for add-ins that use shared folders. With the XML manifest, you specify the permission by setting the SupportsSharedFolders element to true. For details, see Enable shared folders and shared mailbox scenarios in an Outlook add-in. With the unified manifest (preview), you specify this permission with the name Mailbox.SharedFolder in an additional object in the "authorization.permissions.resourceSpecific" array.

The four levels of permissions are cumulative: the read/write mailbox permission includes the permissions of read/write item, read item and restricted, read/write item includes read item and restricted, and the read item permission includes restricted.

You can see the permissions requested by a mail add-in before installing it from AppSource. You can also see the required permissions of installed add-ins in the Exchange Admin Center.

restricted permission

The restricted permission is the most basic level of permission. Outlook assigns this permission to a mail add-in by default if the add-in doesn't request a specific permission in its manifest.

Can do

• Get only specific entities (phone number, address, URL) from the item's subject or body.

• Specify an ItemIs activation rule that requires the current item in a read or compose form to be a specific item type, or ItemHasKnownEntity rule that matches any of a smaller subset of supported well-known entities (phone number, address, URL) in the selected item.

  Note

  Outlook Add-in features that depend on activation rules aren't supported when the add-in uses a Unified Microsoft 365 manifest (preview).

• Access any properties and methods that do not pertain to specific information about the user or item (see the next section for the list of members that do).

Can't do

• Use an ItemHasKnownEntity rule on the contact, email address, meeting suggestion, or task suggestion entity.

• Use the ItemHasAttachment or ItemHasRegularExpressionMatch rule.

• Access the members in the following list that pertain to the information of the user or item. Attempting to access members in this list will return null and result in an error message which states that Outlook requires the mail add-in to have elevated permission.

  • item.addFileAttachmentAsync
  • item.addItemAttachmentAsync
  • item.attachments
  • item.bcc
  • item.body
  • item.cc
  • item.from
  • item.getRegExMatches
  • item.getRegExMatchesByName
  • item.optionalAttendees
  • item.organizer
  • item.removeAttachmentAsync
  • item.requiredAttendees
  • item.sender
  • item.to
  • mailbox.getCallbackTokenAsync
  • mailbox.getUserIdentityTokenAsync
  • mailbox.makeEwsRequestAsync
  • mailbox.userProfile
  • Body and all its child members
  • Location and all its child members
  • Recipients and all its child members
  • Subject and all its child members
  • Time and all its child members

read item permission

The read item permission is the next level of permission in the permissions model.

Can do

• Read all the properties of the current item in a read or compose form, for example, item.to in a read form and item.to.getAsync in a compose form.

• Get a callback token to get item attachments or the full item with Exchange Web Services (EWS) or Outlook REST APIs.

• Write custom properties set by the add-in on that item.

• Get all existing well-known entities, not just a subset, from the item's subject or body.

• Use all the well-known entities in ItemHasKnownEntity rules, or regular expressions in ItemHasRegularExpressionMatch rules. The following example follows schema v1.1. It shows a rule that activates the add-in if one or more of the well-known entities are found in the subject or body of the selected message.

  Note

  Outlook Add-in features that depend on activation rules aren't supported when the add-in uses a Unified Microsoft 365 manifest (preview).

    <Permissions>ReadItem</Permissions>
        <Rule xsi:type="RuleCollection" Mode="And">
        <Rule xsi:type="ItemIs" FormType = "Read" ItemType="Message" />
        <Rule xsi:type="RuleCollection" Mode="Or">
            <Rule xsi:type="ItemHasKnownEntity" 
                EntityType="PhoneNumber" />
            <Rule xsi:type="ItemHasKnownEntity" EntityType="Address" />
            <Rule xsi:type="ItemHasKnownEntity" EntityType="Url" />
            <Rule xsi:type="ItemHasKnownEntity" 
                EntityType="MeetingSuggestion" />
            <Rule xsi:type="ItemHasKnownEntity" 
                EntityType="TaskSuggestion" />
            <Rule xsi:type="ItemHasKnownEntity" 
                EntityType="EmailAddress" />
            <Rule xsi:type="ItemHasKnownEntity" EntityType="Contact" />
    </Rule>
  

Can't do

• Use the token provided by mailbox.getCallbackTokenAsync to:

  • Update or delete the current item using the Outlook REST API or access any other items in the user's mailbox.
  • Get the current calendar event item using the Outlook REST API.

• Use any of the following APIs.

  • mailbox.makeEwsRequestAsync
  • item.addFileAttachmentAsync
  • item.addItemAttachmentAsync
  • item.bcc.addAsync
  • item.bcc.setAsync
  • item.body.prependAsync
  • item.body.setAsync
  • item.body.setSelectedDataAsync
  • item.cc.addAsync
  • item.cc.setAsync
  • item.end.setAsync
  • item.location.setAsync
  • item.optionalAttendees.addAsync
  • item.optionalAttendees.setAsync
  • item.removeAttachmentAsync
  • item.requiredAttendees.addAsync
  • item.requiredAttendees.setAsync
  • item.start.setAsync
  • item.subject.setAsync
  • item.to.addAsync
  • item.to.setAsync

read/write item permission

Specify read/write item permission in the manifest to request this permission. Mail add-ins activated in compose forms that use write methods (Message.to.addAsync or Message.to.setAsync) must use at least this level of permission.

Can do

• Read and write all item-level properties of the item that is being viewed or composed in Outlook.

• Add or remove attachments of that item.

• Use all other members of the Office JavaScript API that are applicable to mail add-ins, except Mailbox.makeEWSRequestAsync.

Can't do

• Use the token provided by mailbox.getCallbackTokenAsync to:

  • Update or delete the current item using the Outlook REST API or access any other items in the user's mailbox.
  • Get the current calendar event item using the Outlook REST API.

• Use mailbox.makeEWSRequestAsync.

read/write mailbox permission

The read/write mailbox permission is the highest level of permission.

In addition to what the read/write item permission supports, the token provided by mailbox.getCallbackTokenAsync provides access to use Exchange Web Services (EWS) operations or Outlook REST APIs to do the following:

• Read and write all properties of any item in the user's mailbox.
• Create, read, and write to any folder or item in that mailbox.
• Send an item from that mailbox

Through mailbox.makeEWSRequestAsync, you can access the following EWS operations.

• CopyItem
• CreateFolder
• CreateItem
• FindConversation
• FindFolder
• FindItem
• GetConversationItems
• GetFolder
• GetItem
• MarkAsJunk
• MoveItem
• SendItem
• UpdateFolder
• UpdateItem

Attempting to use an unsupported operation will result in an error response.

See also

• Privacy, permissions, and security for Outlook add-ins
• Match strings in an Outlook item as well-known entities