[Zope] Pseudo E-Mail Address validation

Hi all, For a subscription tool of a mailing list I'd like to quick-check the e-mail address our users type. Is there a little product/method etc. available that does this? I know that you can only be sure whether an e-mail address exists or not, when you actually send a mail to the user, but a quick-n-dirty check would be nice. Maybe even complete RFC-compliancy as implemented in some Perl-Modules? (spaces, "@" sign, dot-notation etc.) Hoping for an answer, Martin