[KOE-106] Transporting the delivery receipt request in the X-Push-Receipts header.

src/AcaciaZPushPlugin/AcaciaZPushPlugin/Constants.cs

@@ -83,6 +83,13 @@ namespace Acacia
         public const string ZPUSH_HEADER_SIGNATURES_HASH = "X-Push-Signatures-Hash";
 
 
+        #endregion
+
+        #region Delivery receipt requests
+
+        public const string ZPUSH_RECEIPT_REQUESTS = OutlookConstants.NS_TRANSPORT_MESSAGE_HEADERS + "X-Push-Receipts";
+        public const string ZPUSH_RECEIPT_REQUEST_DELIVERY = "delivery";
+
         #endregion
 
         #region Capabilities

src/AcaciaZPushPlugin/AcaciaZPushPlugin/Features/DeliveryReceipts/FeatureDeliveryReceipts.cs

@@ -0,0 +1,50 @@
+/// Copyright 2017 Kopano b.v.
+/// 
+/// This program is free software: you can redistribute it and/or modify
+/// it under the terms of the GNU Affero General Public License, version 3,
+/// as published by the Free Software Foundation.
+/// 
+/// This program is distributed in the hope that it will be useful,
+/// but WITHOUT ANY WARRANTY; without even the implied warranty of
+/// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.See the
+/// GNU Affero General Public License for more details.
+/// 
+/// You should have received a copy of the GNU Affero General Public License
+/// along with this program.If not, see<http://www.gnu.org/licenses/>.
+/// 
+/// Consult LICENSE file for details
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using Acacia.Stubs;
+using Acacia.Utils;
+using Acacia.ZPush;
+
+namespace Acacia.Features.DeliveryReceipts
+{
+    [AcaciaOption("Fixes Delivery Receipt Requests in Outlook, which does not transmit them over ActiveSync.")]
+    public class FeatureDeliveryReceipts : Feature
+    {
+        public FeatureDeliveryReceipts()
+        {
+        }
+
+        public override void Startup()
+        {
+            MailEvents?.ItemSend.Register<IMailItem>(MailEvents_ItemSend);
+        }
+        
+        private void MailEvents_ItemSend(IMailItem item, ref bool cancel)
+        {
+            bool? wantReport = (bool?)item.GetProperty(OutlookConstants.PR_ORIGINATOR_DELIVERY_REPORT_REQUESTED);
+            if (wantReport == true)
+            { 
+                Logger.Instance.Trace(this, "Delivery receipt request: {0}", item.EntryID);
+                item.SetProperty(Constants.ZPUSH_RECEIPT_REQUESTS, Constants.ZPUSH_RECEIPT_REQUEST_DELIVERY);
+            }
+        }
+    }
+}

src/AcaciaZPushPlugin/AcaciaZPushPlugin/Features/Features.cs

@@ -39,6 +39,7 @@ namespace Acacia.Features
             typeof(Signatures.FeatureSignatures),
             typeof(DebugSupport.FeatureDebugSupport),
             typeof(SyncState.FeatureSyncState),
+            typeof(DeliveryReceipts.FeatureDeliveryReceipts)
         };
     }
 }