Subject: How can I receive letters without authentication

From: [email-masked]
Date: Mon, 4 Nov 2002 17:26:59 +0800 (HKT)

hi,I have install sasl and sendmail successfully,and I can 
use the anthentication function when I send mail,but now 
when I receive mail,it also require authentication,so I can
receive any letter from outside.How do I configure so that only when I send a letter using my SMTP server requere authentication but when I recieve a letter from other SMTP
server don't require authentication.
my sasl version is cyrus-sasl-1.5.28,sendmail version is Sendmail-8.12.3
who can help me?thanks very much.