I'm building an emailshot tracking function in my ASP.NET site which will serve up a linked image when the email is opened, so allowing me to count the email opens.It's all above-board, opted-in etc, etc, and I've tried two methods:
calling a \[code\].aspx\[/code\] page that serves (direct to the Response stream) a Base64-encoded image stored in a database
calling a \[code\].ashx\[/code\] HTTP handler that serves an image from a physical folder
Both of these techniques work absolutely fine - the image is served, and I can process the hit in the page code - if I use my POP email or my Gmail accounts.However, Hotmail blocks them both. It doesn't even give the option of displaying images - there's no trace of the original link if I \[code\]View Source\[/code\] on the browser email display. Links to images only seem to display correctly in the Hotmail browser window if I:
Use an actual domain name in the link (rather than an IP address or localhost for testing) AND
Link to physical files (rather than pages that serve them) using \[code\]<img src="http://domain/imagefilename.ext"/>\[/code\].
Is there an alternate approach that will at least give the option of viewing the image? I'm not trying to conceal the tracking in any way - there will usually be other linked images in the emails anyway.Nor does the thing being served have to be an image - is there anything else that can be served (and hence counted) that isn't treated as suspicious by over-zealous mail servers such as Hotmail?Cheers.
