[Exim] Authentication to send, but not receive

Hello,

I've followed the FAQs and examples as best I can, but I've gotten lost
somewhere along the way. I'm trying to set up a server so that local
users can send mail anywhere as long as the authenticate over SSL.

I had this working at one point, but the problem arises that external
mailers cannot send mail in because exim tells them to authenticate. I
think that's the state I'm in now; here are my [relevant?] settings:

tls_advertise_hosts = *
tls_verify_hosts = *
auth_hosts = *
auth_over_tls_hosts = *
host_auth_accept_relay = *

login:
driver = plaintext
public_name = LOGIN
server_prompts = "Username:: : Password::"
server_condition = "${if crypteq{$2}{${extract{1}{:}{${lookup{$1}lsearch{/etc/shadow}{$value}{*:*}}}}}{1
}{0}}"
server_set_id = $1


So everything is working except incoming mail. How do I enable it?

Thanks for any help,
Christopher