Sendmail & Virtual Hosting

Hi guys,

my company is hosting some 20-30 domains. Most of them require to have
some email associated with their domain, aka johndoe.RemoveThis@domain.com.
Untill now I have been using virtual table to redirect the email to
the proper person. I also set a catch all for that domain that sends
all email to /dev/null. But there is a little problem with that
because email to foobar.RemoveThis@domain.com, foobar.RemoveThis@domain.com has not been
defined in virtual table, does not get delivered to nobody, and at the
same time does not bounce the email back to the sender. It just goes
in the black hole. With the spam nowdays that's not bad idea, however,
the problem arises from the following situation. What if the sender
makes a typo in the email address, what if they write
johndo.RemoveThis@domain.com instead of johndoe.RemoveThis@domain.com, then they never
receive a notification that the mail was not delivered, the customer
never gets the email, and what if this was some important business
email.

How can I set sendmail to bounce emails back to the user if that
vitual server does not have the correct email in the virtusertable. At
the same time I want to prevent the following from happening:
** Spammer sends email to non-existing email, email is bounced back
** however, spamers email is not correct, so email is bounced to me,
** I don't have that email on my server, so email is bounce back,
** and so on and on and on.

Is there any trick I can do to achieve this kind of results.


PS: Sorry for posting to stable & ISP at the same time.
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~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Georgi Hristov
IOCC.com, LLC - 800.465.7847
www.iocc.com