Email addresses with .'s in

[root]

HELP!

How do i get qmail to route email address's with .'s in, i.e.

user@domain     userid1
user.surname@domain     userid2

Sendmail used to route these to the individual addresses, i.e. userid2 or
userid1, with qmail all email destined for userid2 goes into userid1's
account.

Is there a solution

Gavin