Issue in processing Unread mails and mark it as read after processing

Question

I'm writing a code to access outlook and process the Unread Mails one by one and mark them as Read (so it won't run on the same mails).

The issue is that it's unable to read all the unread mails. (e.g) suppose in Inbox I'm having 10 mails but it works only for 5 mails. It's processing only half of the mail counts.

After marking as Read, count is reducing but forloop is not iterating for all unread mails, skipping the mails

I wrote it like this:

Outlook.Application outlookApp = new Outlook.Application();

        Outlook._NameSpace oNS;
        Outlook.MAPIFolder oFolder;
        Outlook._Explorer oExp;

        outlookApp = new Outlook.Application();
        oNS = (Outlook._NameSpace)outlookApp.GetNamespace("MAPI");
        oFolder = oNS.GetDefaultFolder(Outlook.OlDefaultFolders.olFolderInbox);
        oExp = oFolder.GetExplorer(false);
        oNS.Logon(Missing.Value, Missing.Value, false, true);

        Outlook.Items items = oFolder.Items.Restrict("[Unread]=true");

        int mailcount = items.Count;

        foreach (Microsoft.Office.Interop.Outlook.MailItem mailItem in oFolder.Items)
        {
            if (mailItem.UnRead) // I only process the mail if unread
            {
                Console.WriteLine("Accounts: {0}", mailItem.Subject);
                mailItem.UnRead = false;                   
            }
        }

Am i missing anything ?Could you please any one help for this?

What's the value of mailcount variable? Can't you iterate items? — Rui Fernandes, Aug 14 '18 at 10:31
if i iterate through items the same issue only occuring.Once i mark as unread mailcount gets reduced. — Rajasekaran Vijayakumar, Aug 14 '18 at 10:33
Have you tried removing `Restrict("[Unread]=true");`? Seems redundant since you are checking each item anyway, and it's probably that filter that is behind the problem. — John Wu, Aug 14 '18 at 10:58
Thanks John,I need to process only unread mails if i remove that restrict condition then code will get all the mails ,then it'll take time to process also. — Rajasekaran Vijayakumar, Aug 14 '18 at 11:01
Then restrict the list by something you don't have an impact on, such as date received. — John Wu, Aug 14 '18 at 11:06

Rui Fernandes · Accepted Answer · 2018-08-16T09:34:55.990

2

Every time that you mark one item as read your 'items' collection is affected (reduced) and that was the problem.

OutLook.Application oApp;
OutLook._NameSpace oNS;
OutLook.MAPIFolder oFolder;
OutLook._Explorer oExp;

oApp = new OutLook.Application();
oNS = (OutLook._NameSpace)oApp.GetNamespace("MAPI");
oFolder = oNS.GetDefaultFolder(OutLook.OlDefaultFolders.olFolderInbox);
oExp = oFolder.GetExplorer(false);
oNS.Logon(Missing.Value, Missing.Value, false, true);

OutLook.Items items = oFolder.Items.Restrict("[Unread]=true");

// Switched to for, https://stackoverflow.com/questions/4317850/do-i-need-to-release-the-com-object-on-every-foreach-iteration#4317878
for (int i = items.Count; i >= 1; i--)
{
     var mail = items[i];

     if (mail.UnRead)
     {
          mail.UnRead = false;
          mail.Save();
     }

     Marshal.ReleaseComObject(mail);
 }

 Marshal.ReleaseComObject(items);

edited Aug 16 '18 at 09:34

answered Aug 14 '18 at 10:40

Rui Fernandes

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@RajasekaranVijayakumar it throws an error or it produces the same result? – Rui Fernandes Aug 14 '18 at 13:38
No error,it produces the same result.half of the mails r skipping – Rajasekaran Vijayakumar Aug 16 '18 at 03:46
I reproduce here your scenario. I'm trying to find the issue. I will give some feedback soon :) – Rui Fernandes Aug 16 '18 at 09:07
@RajasekaranVijayakumar problem solved :) see the explanation in the answer :) – Rui Fernandes Aug 16 '18 at 09:29
Hi Rui Fernandes,Thanks ,your suggestion helped me. – Rajasekaran Vijayakumar Aug 20 '18 at 07:12
Attention: Use a ``for`` loop but MAKE SURE it's a ``DECREMENT For Loop``; otherwise, you will experience the same behavior you are looking to solve. – Geovani Martinez Nov 30 '22 at 16:25

Issue in processing Unread mails and mark it as read after processing

1 Answers1