Sitting behind a dynamic IP means that your going to get blocked by a lot of SMTP servers if you send directly from that IP address. Most ISPs allow their SMTP servers to be used as relay Smart Hosts; so when you send an email out to the internet it will relay to your ISPs SMTP server and then send from there…from that IP address.
Its a pretty simple thing to set up in Exchange System Manager:
- In Connectors, right-click on Internet Mail SMTP Connector and choose Properties.
- Change the radio buttons to: Forward all mail through this connector to the following smart hosts
- Enter your ISPs SMTP server in here, if you have the IP be sure to enter it within square brackets, below is the address for iiNet in Australia.
- All SMTP servers these days require authentication to send outbound through them, so select the Advanced tab.
- Then click Outbound Security
- Choose Basic authentication
- Click Modify
- Enter your ISP user name and password and click OK
The Exchange server is now setup to relay outbound mail through your ISP, so that should see all your mail successfully arrive at it’s destination 100% of the time. But be sure to test it out and check that your ISP allows the use of a Smart Host.
For inbound email I have also now added a 2nd MX record for my domains which points to my web server (which is how I used to have email set up), which means I will have another layer of redundancy for inbound emails, should I lose my ISP connection for the server or it crashes etc.
Now time to kick back and wait for the emails to flood in, though not SPAM anymore!
