Question

I’m adding an img tracking pixel to items that have embedded content using my outlook addin which allows me to track when the person has open the email (pretty standard practice)

I do this by adding an image tag right before the closing body tag upon the send event.

The problem is, outlook then calls the url three times (twice with a method of “OPTIONS” and once with “GET”), this defeats the whole purpose of the tracking pixel because it triggers the event on send.

Does anyone know why outlook makes these requests, or how to get around this?

Answer 1

I see two possibilities:

Either Outlook or Exchange Server is checking the eMail content before sending it

OR

Outlook is configured to “When an HTML message contains pictures located on the Internet, send a copy of the pictures instead of the reference to their location” – for changing that setting in Outlook 2007/2010 via Registry see http://www.msoutlook.info/question/72

BTW: the two OPTIONS calls let me believe that Outlook is somehow checking the server of the linked image for WebDAV and/or Frontpage extensions…