Yosemite Home Mail server from Static ISP or registrar?

Hello Again,

Yosemite Home Mail server from Static ISP or registrar?

Im practicing Yosemite Server by hosting it at home on a static IP and am ready to kick in some collaboration services.

In all logic in my head, Mail configrations should precede all other services.

DNS :

So I have example.com registered

I have an @ pointing at my iP for A record.

I have no aliases (CNAME), forwarding URL, stealth or anything else for now.

I probably going to need an MX record too

SSL :

I have an inexpensive SSL certificate from Comodo for example.com and www.example.com.

Internet Line :

I am behind a subcontracted DSL from a major Québec, Canadian ISP

The direct ISP also feeds me a static IP.

The modem I have is in bridge mode.

NAT :

My airport Extreme It is controlled by OS X Server.

- Internet tab: gets the static IP at its base, /32 Netmask and ISP router address

DNS server is Yosemite server address 10.0.1.2

Domain name: example.com

- Network Tab

Does DHCP for 10.0.1/24 for 100…200 range

Has a reserved Eth MAC to IP address for MacMini Server at 10.0.1.2 named xyz@example.com

Poert setting show DNS, Websites and Profile Mamager

Server:

- OS System Preferences > Network> Ethernet

IPv4 Manually, IP 10.0.1.2, netmask 255.255.255.0, Router 10.0.1.1

DNS Server 127.0.0.1 Search Domain: example.com

Server App: - DNS

Permissions: Private Network

Settings: 2 ISP DNS IP and Google DNS

Forward lookups: Only Some Clients : Server itself and clients on local network

- Records:

- Primary Zone:

www.example.com alias

xyz.example.com machine

xyz.example.com nameserver

- Reverse Zone:

www.example.com alias

10.0.1.2 reverse mapping

xyz.example.com nameserver

Server App - Mail

- Access

Status: Offline (for now)

Permissions All users, All network (Isn't this an open mail relay?

- Settings

Authentiacation: Automatic

Push Notoification Enabled

- Filtering Virus and Junk: Enabled

Blacklist zen.spamhaus.org

Graylist filetering Enabled

Junk Mail filtering enabled : Aggressive

Nothing in domains.

I only have DNS, OD, Websites and Caching services on for now.

== Questions ==

1- Should I configure Mail service relay from Static ISP or registrar?

Then : Which setting do you recommend for mail?

François.