Forum OpenACS Q&A: Can anonymous email for a domain on a shared server be done?

I'm working on a dating-service site that is supposed to have
anonymous email. So, I set up some a Perl script on my Linux box that
would get email redirected to it by procmail and the script would
take care of changing the "To:" header after doing a lookup of what
alias corresponds to the what email address (and vice versa for
the "From:" line).

All was OK while I was bouncing email around between actual users on
my Linux box but things went awry when I sent email to a non-existent
user (to simulate mail going to an aliased email address). Postfix
didn't like that.

While it occurred to me that I might be able to get around this by
having aliases created and/or Linux users when people register, this
may not be so great on the actual box that the site is going to live
on. Aside from not really wanting to muck with system files if I
don't have to, the domain is a virtual host on a shared server--so
even if I wanted to muck with system files, I probably won't be able
to.

So, the question is: is it possible to set up anonymous email on a
virtual host on a shared server without having (or needing) root
access? For what it is worth, I think the hosting service is using
Sendmail.

Thanks for your input.

P.S. I know that one could set up a web-based service, where you get
emails sent to you and if you want to reply, you have to click on a
link that brings you to the web site and you send email from there.
While this would work, it is not the desired behavior--right now, we
want email to work as normally as possible.

It's pretty trivial to get postfix (and I'm sure sendmail) to send all users @ somedomain that don't match "real" users to a "collection" user.  Then have procmail run on that user's mail only.

It's not something you can do without root, but the mta part is so simple to set up I'd be surprised if you couldn't find a host willing to do that for you.  The procmail part of course wouldn't require root.