I have a client that wants to know when a user of our site actually reads one of our e-mails. We, of course, have a unique ID for each user (actually randomally generated, so that they cannot walk through our DB), which might be useful. <BR><BR>His idea is that once the user gets the e-mail (which is generated by CDONTS and might go to hundreds of folks) and it is looked at, the page will somehow send back their unique id so that we can catalogue that info... Any ideas? Impossible? A security issue? Lots of response encouraged!