Question

I am writing an Outlook Addin using AddIn Express.

I use Delphi, anyway the problem relates to everyone writing Outlook AddIns so i include c# in the tags.

var
  MItem: _MailItem;
  [...]

  if OutlookApp.ActiveExplorer.Selection.Item(i).QueryInterface(IID__MailItem, MItem) = 0 then
  [...]

this lines fires an exception at customer end. The problem is that if on that customer outlook i try to see the message details (in outlook 2010 i open the message i go on File tab in ribbon and then i click on properties) I got this:
.

If I save the problematic message as msg file and i move it to my local outlook (dragging it in some folder so it becomes “one of my emaii messages”) I open the properties and i can see the headers.

So somehow there is an issue with that particular Outlook installation. Is it an issue or is it a Outlook setting? I also noticed that there are 3 types of behaviour:

1) message is fine (at my end all messages are “fine”, while at customer’s end only some of them are fine. By fine I mean: Internet hedaers are complete)

2) message is not perfect (on some messages the internet headers are incoplete, for example Message-ID headers is missing – in this case anyway the above code works)

3) message is bad (no headers as in screenshot and the code fails).

One more thing: sending a message at customer end to the customer address (so sender = reciever) i see that on sent folder the message is “bad” and on inbox the same message is fine.

Can anyone help me shedding some light on this?

Edit: I noticed that at my end even if I see the hedaers the exception still throws. I am even not able to see the exceptino message. This is probably because of addin express (i have the non source code version).

Answer 1

The message doesn’t get an internet header until it leaves your corporate email setup, hence the name.

What’s stored in your Sent Items is not the same as what has gone out into the world

Have you tried troubleshooting the exception with AddIn Express? If you give them enough info to repro the problem they will surely help you? It’s probably a NullReferenceException anyway is it?