Mail is not delivered from the Internet to my Exchange 2003 server

Question

Recently we moved from mailenable to exchange 2003 It was kinda a shocker to configure it, but i managed to configure it... kinda:

Mail within the intranet works fine; the same for smtp/owa/oma/pop3/imap

And users can send mail to any outside address

But... mail coming from the internet cannot be delivered; for example this is the log of hotmail trying to deliver mail:

#Software: Microsoft Internet Information Services 6.0
#Version: 1.0
#Date: 2009-08-04 01:08:24
#Fields: time c-ip cs-method cs-uri-stem sc-status 
09:49:18 65.55.116.22 EHLO - 250
09:49:18 65.55.116.22 MAIL - 454
09:49:18 65.55.116.22 QUIT - 240
09:50:17 65.55.116.22 EHLO - 250
09:50:17 65.55.116.22 MAIL - 454
09:50:17 65.55.116.22 QUIT - 240
09:51:42 65.55.116.109 EHLO - 250
09:51:42 65.55.116.109 MAIL - 454
09:51:42 65.55.116.109 QUIT - 240
09:52:42 65.55.116.109 EHLO - 250
09:52:42 65.55.116.109 MAIL - 454
09:52:42 65.55.116.109 QUIT - 240
09:58:13 65.55.37.72 - - 0
09:58:13 65.55.37.72 EHLO - 0
09:58:13 65.55.37.72 - - 0
09:58:13 65.55.37.72 MAIL - 0
09:58:13 65.55.37.72 - - 0
09:58:13 65.55.37.72 RCPT - 0
09:58:13 65.55.37.72 - - 0
09:58:13 65.55.37.72 BDAT - 0
09:58:13 65.55.37.72 - - 0
09:58:13 65.55.37.72 QUIT - 0
09:58:14 65.55.37.72 - - 0

the mx on my dns is set correctly, because i can send correctly email from the internet through authenticated smtp

what's wrong? since the smtp connector is set to be used with a password, the external servers cannot send mails to me? How i can set it in a way that won't make me an open relay?

Answer 1

In order to receieve email from external sites, you do need to allow anonymous authentication but you also just need to set the list of IP addresses that are allowed to relay on the SMTP connector. By restricting the IP list to your internal IP range, you will prevent yourself from becoming an open relay.