Disable authentication for submission service

Hello,

Is it possible to disable the requirement for authentication on the submission service? I'm trying to require authentication for all, except for a handful of IP addresses.

Thank you.

ehlo test.com 250-aaa 250-AUTH PLAIN LOGIN 250-BURL imap 250-CHUNKING 250-DSN 250-ENHANCEDSTATUSCODES 250-SIZE 250 PIPELINING MAIL FROM:test@test.com 530 5.7.0 Authentication required.