Using MAPI to open an Outlook folder, MAPIFolder.Items.Sort("Subject",True) does not sort

Question

//

type here

I need to sort the emails in a particular folder by Subject Ascending. Using Sort on the Folder does not sort the Items.

//To confirm this I have outputted the email Subject values to an Excel file and tried ascending,    descending and no sorts but nothing makes a difference in the output order.

Here is the code and a subset of the output to show the lack of sorting. //C# Code using Microsoft.Office.Interop.Outlook; using System.Runtime.InteropServices; using Excel = Microsoft.Office.Interop.Excel;

  namespace DictionaryCollection_test_bed
  {//Namespace
      class Program
      {//Program
          static void Main(string[] args)
          {//Main
          //Open an Excel app to enter Outlook emails in the oprder they 
                //were processed
              Excel.Application xlTest = new Excel.Application();
              Excel.Workbook xlWorkbookTest = xlTest.Workbooks.Open(sFilePath + "\\SepticTest.xlsx" );
              Excel._Worksheet xlWorksheetTest = xlWorkbookTest.Sheets[1]; // 

                //Open the Outlook file
              Microsoft.Office.Interop.Outlook.Application outlookApp = new Microsoft.Office.Interop.Outlook.Application();
              // Log in to Outlook
              NameSpace outlookNamespace = outlookApp.GetNamespace("MAPI");
              outlookNamespace.Logon();
              MAPIFolder OLAccount = outlookNamespace.Folders[sAccountName];
      MAPIFolder OLFolder = OLAccount.Folders[sFolderName];
          OLFolder.Items.Sort("[Subject]", false);//It makes no difference whether the secod 
                                                      //param is true or false
                        //or Sort is omitted
   
             Try
               {//Try
             int iRowCount += 1;
             foreach (MailItem eMail in OLFolder.Items)
             {
              xlWorksheetTest.Cells[iRowCount, 1] = eMail.Subject; //Output to the test workseet
              iRowCount += 1;
             }
               }//Try

               {//Catch
         catch (System.Exception ex) //when (ex.Message.Contains("(E_NOINTERFACE)") ==  false)  
               {//Catch
         Finally    
         {//Finally
                  xlWorkbookTest.Save();
                  xlWorkbookTest.Close();
                  xlTest.Workbooks.Close();

                  outlookNamespace.Logoff();
                  System.Runtime.InteropServices.Marshal.ReleaseComObject(outlookNamespace);
                  System.Runtime.InteropServices.Marshal.ReleaseComObject(outlookApp);

                  System.Runtime.InteropServices.Marshal.ReleaseComObject(xlWorksheetTest);
                  System.Runtime.InteropServices.Marshal.ReleaseComObject(xlWorkbookTest);
                  System.Runtime.InteropServices.Marshal.ReleaseComObject(xlTest);

               }//Finally
      }//Main
      }//Program
  }//Namespace

//Output sorted ascending, descending or not sorted
FW: 57-4-2, 2620  EDENTON RD,  , 2000 gal, 10/13/2023
FW: 57-5-2, 379  STREET RD,  , 1750 gal, 10/18/2023
FW: 57-7-1.1, 149  CHEEK RD,  , 1250 gal, 9/12/2023
FW: 57-7-22.2A, 130  WINDEMERE LA,  , 1750 gal, 9/13/2023
FW: 57-8-23.2A, 170  SHERROCKEE LA,  , 3000 gal, 9/14/2023
FW: APPROVED - HD - Sewage Permit, 10/12/202357-3-3, 5260  HOMEVILLE RD, 
FW: 57-8-2.2, 409  PUSEY MILL RD,  , 1250 gal, 10/18/2023

Answer 1

You are sorting one collection, and showing the elements of a completely different collection - every time you call MAPIFolder.Items, you get back a brand new Items collection that has no knowledge of any other instances of that object.

Store MAPIFolder.Items in a dedicated variable, sort it, then loop through it.