A client of mine has a newsletter setup on his site that sends out a weekly email updating prople on the new products that theys ell, these people are double optin subscribers that have joined his site to post things for sale and check out things to buy etc

He wishes to know how many people out of the mailing list that receive the email actually open it and read it and how many click through to teh site

Well i can manage the click tracking with a simple php script thats no problem

But i need to know how i can track email opens

I know that theres some way of doing it with an image that uses a php script to generate it and tracks the hit at the same time or something but i cannot figure out how exactly to get that working, and iknow that some people dissable images in email to stop tracking and some have text based email

But this is what my client wants so if i can at least put something together to monitor some of his list that would be great

Thanks in advance for any help