Don: > I have been working on a program to validate email > addresses (syntax only) = > to filter out obviously bad addresses from internal > files/databases prior = > to loading into a listserv list. My questions are "what is > a valid email = > address?", and "where do I go to find the authorative > definition?" I don't know what platform you're developing this for, but a couple of years ago, Tom Christensen sent me a perl script that we've been using for some time to do as much error checking as possible on form-input e-mail address submisstions. It's not a big script but I suspect it will not run on all platforms (we run it on a UNIX platform). If you know perl, I suppose you could convert the logic to another language. The program checks for all the potential syntax errors and also has some editorial filters (many of which I deleted) that screen out usernames like "webmaster" or "username" or "root" or that have repetive characters in them (i.e. [log in to unmask]). It also validates the deliverability of the domain by checking if there is an MX record for the domain. Beyond that, final validation of e-mail is confirmed when an actual attempt to deliver is made. If you like, I can send you that script privately. Mark Hunnibell