Outlook - Interop asking if I want to approve a certificate

Question

I'm using interop to get me a list of all local outlook contacts (code below). It all works fine except for one case: When I don't have outlook open during the time Iam using that code I get a messagebox which disappears after about 2 seconds again. The messagebox asks me (translated thus the english version is probably slightly different): "Configuring mailboxxyz-accept Server configuration for this website?"

After looking at the message and looking how the local things are configured I saw that my company is using a certificate in outlook and as it is looking it is so that:

If outlook is running then my interop functions are using the certificate and thus the messagebox does not pop up
If outlook is not running then my interop functions are not automatically using the certificate and thus the popup comes and asks if I want to accept it.

What adds a layer of strangeness there is that the usage of the functions succeeds and the messagebox pops up a few seconds AFTER the functions have finished and then disappears after 2 seconds.

Microsoft.Office.Interop.Outlook.Application outlookHandler = new Microsoft.Office.Interop.Outlook.Application();
Microsoft.Office.Interop.Outlook.Items outlookItemsCollection;
MAPIFolder folderContacts = (MAPIFolder)outlookHandler.Session.GetDefaultFolder(OlDefaultFolders.olFolderContacts);
outlookItemsCollection = folderContacts.Items;

foreach (var outlookItem in outlookItemsCollection)
{
    .....
}

Also another way to get this phenomenon: When outlook is not running I can try to start it:

   Microsoft.Office.Interop.Outlook.Application outlookHandler = new Microsoft.Office.Interop.Outlook.Application();
        var mm = outlookHandler.GetNamespace("MAPI");
        mm.Logon(Type.Missing, Type.Missing, true, true); 
        // Same for the second true being false instead.

When I do this outlook asks for the certificate after asking for the default profile.

My question here is now: Is there any way to prevent this popup from happening (or to tell the interop methods to use the certificate without asking)?

Is it that each outlook client has a certificate, or that the exchange server is using a certificate which outlook clients have to accept? — Daniel Lane, Aug 29 '14 at 11:03
The exchange server is using a certificate as far as I'm aware — Thomas, Aug 29 '14 at 13:46
It sounds to me like you might be getting an SSL error and that's causing your interop to fall over. I could be wrong though. Is your program throwing any exceptions at all? — Daniel Lane, Aug 29 '14 at 14:08
You may wish to set the Microsoft.Office.Interop.Application.Visible property to true to see what the prompts are telling you. — Daniel Lane, Aug 29 '14 at 16:58

score 1 · Answer 1 · answered Aug 29 '14 at 14:42

I'm going to preface this with the fact that this isn't an elegant solution, it should however work.

// check to see if outlook is running
System.Diagnostics.Process[] prcs = System.Diagnostics.Process.GetProcessesByName("outlook");
// if the found prcs length is 0, outlook isn't running
if(prcs.Length == 0)
{
    // start outlook
    System.Diagnostics.Process.Start("path to outlook");
    // wait for outlook to load
    // call your interop code
}
else
    // outlook was found as an open process
    // call your interop code

This works around your issue rather than resolving the underlying issue. Without an exception or anything else it's difficult to actually get to the bottom of.

Outlook - Interop asking if I want to approve a certificate

1 Answers1