This is exactly what I do.  I have a separate account on one of our
Unix boxes that I point all my list errors to.  Then I use Pine :) with
sorting by subject to read the errors.  I can usually dump most duplicates
without even looking at them (exceptions are AOL and Compu$erve, since
multiple errors from those sites may indicate different subscribers causing
the errors).  Many mornings I wake up to 400-500 error messages in my
error account, but in reality I can often pare these down to say 50-75
without even breaking into a sweat. :)  And those I generally cut and
paste into a Windows Notepad file so I can send one big job instead of
several small ones.
 
The problem with such a strategy is that not all list owners have the
ability to create themselves another account.  I remember when I was
at INDYCMS with one account, trying to handle list errors and regular
e-mail all together.  The Eudora strategy would probably be best for
those with a single account that's POP-accessible, but I don't use
Eudora, so I'm not the person to ask.
 
Nathan