How to setup DNS behind Airport Extreme and ISP that will not reverse DNS

Hi,

I am having issues setting up my Mac Mini with SLS. Right now my server is connected to the internet through my Airport Express. It gets a static address from the router (10.0.1.13). The router also has a static address from my ISP. I own the domain redcedarpoint.com. I have set the A record to point to my static router IP address. I also setup a CNAME for server.redcedarpoint.com to the same address.

During the initial portion of setup SLS sees my ISP's domain versus my own domain and incorrectly fills the local domain name. I manually changed these to redcedarpoint.com and called the server 'server'. This puts server.redcedarpoint.com into all the host names. Everything seems to work, but now all my users get email addresses like johndoe@server.redcedarpoint.com versus johndoe@redcedarpoint.com. I have manually set mail host name to redcedarpoint.com (although this is wrong I think). It solves the email addressing issue, but now postfix gives me a warning about a duplicate:

+Jan 27 21:20:45 server postfix/postmap[70670]: warning: /var/amavis/local_domains.db: duplicate entry: "redcedarpoint.com"+

My question is: What should I fill in during setup and how should I setup DNS from my hosting service.

By the way, I am also trying to funnel all inbound and outbound email through my premium Google Apps subscription.

Here's also the result of postconf -n

+Last login: Wed Jan 27 21:19:47 on ttys000+
+server:~ ianknight$ postconf -n+
+biff = no+
+command_directory = /usr/sbin+
+config_directory = /etc/postfix+
+content_filter = smtp-amavis:[127.0.0.1]:10024+
+daemon_directory = /usr/libexec/postfix+
+debug peerlevel = 2+
+enable serveroptions = yes+
+header_checks = pcre:/etc/postfix/custom headerchecks+
+html_directory = /usr/share/doc/postfix/html+
+inet_interfaces = all+
+mail_owner = _postfix+
+mailbox sizelimit = 0+
+mailbox_transport = dovecot+
+mailq_path = /usr/bin/mailq+
+manpage_directory = /usr/share/man+
+maps rbldomains =+
+message sizelimit = 10485760+
+mydestination = $myhostname, localhost.$mydomain, localhost, dmcwatering.com, internationalcardio.com+
+mydomain = redcedarpoint.com+
+mydomain_fallback = localhost+
+myhostname = redcedarpoint.com+
+mynetworks = 127.0.0.0/8,216.239.32.0/19,64.233.160.0/19,66.249.80.0/20,72.14.192.0/18,209.8 5.128.0/17,66.102.0.0/20,74.125.0.0/16,64.18.0.0/20,207.126.144.0/20,173.194.0.0 /16+
+newaliases_path = /usr/bin/newaliases+
+queue_directory = /private/var/spool/postfix+
+readme_directory = /usr/share/doc/postfix+
+recipient_delimiter = ++
+relayhost =+
+sample_directory = /usr/share/doc/postfix/examples+
+sendmail_path = /usr/sbin/sendmail+
+setgid_group = _postdrop+
+smtp sasl_authenable = yes+
+smtp sasl_passwordmaps = hash:/etc/postfix/sasl/passwd+
+smtpd clientrestrictions = permit_mynetworks permit saslauthenticated reject rblclient zen.spamhaus.org permit+
+smtpd enforcetls = no+
+smtpd helorequired = yes+
+smtpd helorestrictions = reject invalid_helohostname reject non_fqdn_helohostname+
+smtpd pw_server_securityoptions = cram-md5,gssapi,login+
+smtpd recipientrestrictions = permit saslauthenticated permit_mynetworks reject unauthdestination check policyservice unix:private/policy permit+
+smtpd sasl_authenable = yes+
+smtpd tlsCAfile =+
+smtpd tls_certfile =+
+smtpd tls_excludeciphers = SSLv2, aNULL, ADH, eNULL+
+smtpd tls_keyfile =+
+smtpd tlsloglevel = 0+
+smtpd use_pwserver = yes+
+smtpd usetls = no+
+unknown local_recipient_rejectcode = 550+
+virtual aliasmaps =+
+server:~ ianknight$+