emails receipt

hi,we developed email s/w in asp.net application code behind is vb.i want to know how to get email receipt whether the emails as read or not? by the customers

if the emails as read i want to getback the email receipt. how to track this? anybody can help me in this issues.

thanks

prakash

Unless you use a tracking image in an html formatted email, this is an exercise in futility. Even the tracking image will not work most of the time. You can set a header to ask for a receipt, but many users have this turned off anyways.

I would think that your webmail client should offer, a "read receipt" or "receipt on delivery" which would be the option you want.