If you are planning to more or less auction some
of the cels anyway, why not put them on the free
animanga auctions? Also, if your e-mail does not
work, why not temporarily set up a hotmail
account? It's a free service and is pretty
stable - (obviously there are other free e-mail
services out there too). If you are getting
swamped, you might ask some of the professional
dealers how they handle it, they seem able to
process close to a hundred e-mails/orders in just
a few days.
Hope this helps!