Thank you both for your uber rapid responses; much appreciated. I've dropped an email to the [email protected] but unfortunately I got a 550 back.
It looks like twitter.com is using Google apps for their email, and so they might not have set up a catchall mechanism to process invalid email addresses. Maybe in the past they were using a different mta and thus had a different setup (to support such emails), but it doesn't look like it now. Thanks again, James
