Any sane email client will (or, at least, can be configured to) send a plain text version alongside the HTML version.

If your correspondents have their email client misconfigured so it doesn't do that, then I'd be very tempted to simply return the message to them with an appropriate message ("My email client will not read HTML email as the javascript often found within such messages can be dangerous, please resend in plain text"). It would be very easy to configure something like Procmail to do that automatically.

It's all very well applying a local patch, but I think you'll find it far more satisfying in the long term to fix the source of the problem.

--
<http://www.dave.org.uk>

"The first rule of Perl club is you do not talk about Perl club."
-- Chip Salzenberg