Follow this link to set up Postfix to use GMail as your SMTP server.
Step 0 :
Apply of free Google Apps (Free) Email :
Google Apps (Free) Email
Step 1 :
Create the MX record at your domain automatically.
Create the MX record at your domain manually.
The MX record are :
ASPMX.L.GOOGLE.COM
ALT1.ASPMX.L.GOOGLE.COM
ALT2.ASPMX.L.GOOGLE.COM
ASPMX2.GOOGLEMAIL.COM
ASPMX3.GOOGLEMAIL.COM
Step 1a :
Create a SPF record
Step 2 :
You will receive a email from Google and ask you to create a adminstrator account with your domain name. Your domain name needs to be authorized to use Google Apps. You should follow the instructions to complete the process.
After that, you can you GMail as your domain's email.
Step 3 (Optional) :
If you are using Untangle as gateway and IPS, you should do the following :
Open a browser and point to Untangle web page as well as login.
Config/Networking/Hostname
Change the following settings :
From -
Hostname : untangle.mydomain.com
To -
Hostname : untangle.mydomain.local
Step 3a (Optional) :
Config/Email/Outging Email Server (SMTP)
Change the following settings :
Send Email using the specified SMTP Server
- Server Address or Hostname : <postifx server IP address>
- Server Port : 25
Known issue
Cannot send to yourself with your domain, e.g. yourname@yourdomain.com via Untangle.
That's all! See you.