Office 365 Mail Rest Api is not Returning "ContentBytes" property of an email attachment. RRS feed

  • Question

  • How to get ContentBytes property of an email attachment using office 365 rest api? I am using node.jsbelow is the code which i am using

    outlookClient.me.folders.getFolder('Inbox').messages.getMessages().filter('IsRead eq false and HasAttachments eq true').fetchAll(10).then(function (result) {
    result.forEach(function (message) {
        message.attachments.getAttachments().fetchAll(100).then(function (attachmentResult) {
            console.log('Message "' + message.subject + '" contains ' + attachmentResult.length + ' attachment(s)');
            attachmentResult.forEach(function (attachment) {
              console.log('*    "' + attachment.name + '" (' + attachment.size + ' KB)');


    in above code i am able to get all the details of attachment except ContentBytes,

    I wan to get all attachment type(item attachment and file attachment) content bytes from an email.

    please suggest me how can i get the ContentBytes of an attachment.

    • Edited by rvkp Sunday, August 9, 2015 3:52 PM
    Sunday, August 9, 2015 3:52 PM


  • Hi rvkp,

    >> Office 365 Mail Rest Api is not Returning "ContentBytes" property of an email attachment

    Based on the API below, FileAttachment contains ContentBytes, but ItemAttachment did not contain ContentBytes.

    # Resource reference for the Mail, Calendar, and Contacts REST APIs

    With getAttachments, it return the ItemAttachment list instead of FileAttachment. With C#, you could convert the ItemAttachment to FileAttachment. Something like below:

                var outlookServicesClient = await AuthenticationHelper.EnsureOutlookServicesClientCreatedAsync("Mail");
                var messages = await outlookServicesClient.Me.Folders["Inbox"].Messages
                    .Where(m => m.HasAttachments == true)
                    .Expand(m => m.Attachments)
                foreach (var message in messages.CurrentPage)
                    var attachments = message.Attachments.CurrentPage;
                    foreach (FileAttachment attachment in attachments)
                        byte[] test = attachment.ContentBytes;

    But I am not sure whether this way could be achieved in javascript. If this could not be achieved, I think you need to get the specific attachment with message_id and attachment_id and use http request to get attachment. In the response of the Get an attachment (REST), it will return ContentBytes.

    # Get an attachment (REST)

    Best Regards,


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    Monday, August 10, 2015 1:46 PM