EWS Managed Api - Attachment URL

Question

I am using EWS Managed Api 2.2 and Exchange Server 2010_SP2. I am developing something to get attachment of email. I am wondering if I can get the url of any attachment in email to access from anywhere.

Thanks

To my knowledge, no you cannot do this. EWS will only provide access to the mail message itself which in turn encapsulates any attachments. You could install some sort of transport agent and download all of the mime data and then convert the mime data to some type of eml file with attachments and reference them that way. — Tdorno

Chris Barnes Chris Barnes · Accepted Answer · 2015-08-05T18:06:52

You can, but it might not be that pretty. In summary, you can use WebClientReadFormQueryString as a basis for constructing the link to an attachment. The attachments, in OWA, have the same id as the parent message. Below is what I did to construct the link.

using System;
using System.Collections.Generic;
using System.Collections.Specialized;
using System.Linq;
using System.Web;
using System.Diagnostics;
using System.IO;
using Microsoft.Exchange.WebServices;
using Microsoft.Exchange.WebServices.Data;
using Microsoft.Exchange.WebServices.Auth;


/******************************************************/
    //pass WebClientReadFormQueryString and the attachment index value
    private static string makeAttachmentLinkForOWA(string queryString, int itemNum = 0)
    {
        //extract the id. The url encoding is lost
        NameValueCollection queryCollection = HttpUtility.ParseQueryString(queryString);

        //apply url encoding to the extracted id
        string msgId = HttpUtility.UrlEncode(queryCollection.Get("id"));

        //this is to increment attid0
        char attachmentLetter = Convert.ToChar(itemNum + 65);

        //build the query prefix
        string a = "https://webmail.myorg.org/owa/attachment.ashx?attach=1&id=";

        //build the attachment postfix. attid0 works with documents (docx, xls, etc.) but failed on .wav
        string b = String.Format("&attid0=BAA{0}AAAA&attcnt=1", attachmentLetter.ToString());

        //its broken if there isn't a messageId
        if (msgId == null)
        {
            return null;
        }
        else
        {
            //build the link
            string link = String.Format("{0}{1}{2}", a, msgId, b);

            return link;
        }
    }

EWS Managed Api - Attachment URL

1 Answers