message: replyAll

Namespace: microsoft.graph

Reply to all recipients of a message using either JSON or MIME format.

When using JSON format:

  • Specify either a comment or the body property of the message parameter. Specifying both will return an HTTP 400 Bad Request error.
  • If the original message specifies a recipient in the replyTo property, per Internet Message Format (RFC 2822), send the reply to the recipients in replyTo and not the recipient in the from property.

When using MIME format:

  • Provide the applicable Internet message headers and the MIME content, all encoded in base64 format in the request body.
  • Add any attachments and S/MIME properties to the MIME content.

This method saves the message in the Sent Items folder.

Alternatively, create a draft to reply-all to a message and send it later.

This API is available in the following national cloud deployments.

Global service US Government L4 US Government L5 (DOD) China operated by 21Vianet


Choose the permission or permissions marked as least privileged for this API. Use a higher privileged permission or permissions only if your app requires it. For details about delegated and application permissions, see Permission types. To learn more about these permissions, see the permissions reference.

Permission type Least privileged permissions Higher privileged permissions
Delegated (work or school account) Mail.Send Not available.
Delegated (personal Microsoft account) Mail.Send Not available.
Application Mail.Send Not available.

HTTP request

POST /users/me/messages/{id}/replyAll
POST /users/{id | userPrincipalName}/messages/{id}/replyAll
POST /me/mailFolders/{id}/messages/{id}/replyAll
POST /users/{id | userPrincipalName}/mailFolders/{id}/messages/{id}/replyAll

Request headers

Name Type Description
Authorization string Bearer {token}. Required
Content-Type string Nature of the data in the body of an entity. Required.
Use application/json for a JSON object and text/plain for MIME content.
Prefer: outlook.timezone string Sets the time zone for the Sent field of the reply message in HTML that this API creates based on the request body. The value can be any of the supportedTimeZones configured for the user. If not specified, that Sent field is in UTC.

Use this header only if you're specifying the Content-Type: application/json header to create the reply message in HTML. If you use the Content-Type: text/plain header, this Prefer header does not have any effect. Optional.

Request body

When using JSON format, provide a JSON object in the request body with the following parameters.

Parameter Type Description
comment String A comment to include. Can be an empty string.

When specifying the body in MIME format, provide the MIME content with the applicable Internet message headers, all encoded in base64 format in the request body. This method loads the sender and all recipients of the original message as recipients of the new message.


If successful, this method returns 202 Accepted response code. It doesn't return anything in the response body.

If the request body includes malformed MIME content, this method returns 400 Bad request and the following error message: "Invalid base64 string for MIME content".


Example 1: Reply-all in JSON format to a message

Here is an example of how to call this API.


Here is an example of the request.

Content-type: application/json

  "comment": "comment-value"

Here is an example of the response.

HTTP/1.1 200 OK

Example 2: Reply-all in MIME format to a message

Content-type: text/plain


Here is an example of the response.

HTTP/1.1 202 Accepted

If the request body includes malformed MIME content, this method returns the following error message.

HTTP/1.1 400 Bad Request
Content-type: application/json

    "error": {
        "code": "ErrorMimeContentInvalidBase64String",
        "message": "Invalid base64 string for MIME content."