IP – Internet Protocol (IP) address is the identifying number assigned to every device connected to the internet.
Domain Name – A domain name is text that links to an IP address. It is used to access a website. A domain name is the name that a user types into a browser to reach a website. The domain name for Google is ‘google.com’.
DNS – The Domain Name System (DNS) is like a phonebook for the Internet. It enables Domain Names to be converted to IP addresses.
ISP – Internet Service Provider. The company you get your internet from. In Australia, Telstra, Optus, Vodaphone, TPG, Aussie Broadband etc.
Email Spoofing -sending email messages with a fake sender address. In cases where you have and email address issued on your Domain Name, Email Spoofing involves someone other than the Domain Name owner sending out fake emails under that name.
Recently, I had a number of non-delivery notices from emails I had sent from my email address on my Domain – Whysun.com.
I have several security measures in place to stop Email Spoofing and they depend on quoting the correct IP.
As soon as I started receiving the non-delivery notices, I assumed that my ISP had changed my IP. When you “get the internet” from an ISP, you are in fact buying one IP address and you use your router to link that one IP address to your various devices either by Wi-Fi or Ethernet (cord).
Most ISPs in Australia offer Dynamic IP addresses. In other words, the ISP can change the IP address at any time. You can buy a Static (fixed) IP address, but the ISP does not usually change the IP address all that often. Unless you have a reason for a static IP, it does not matter if the IP changes. Most people just accept a Dynamic IP as they have no reason for a static IP. In cases where you might have a reason to have a static IP, many people (including myself) just accept a Dynamic IP instead of paying extra for a fixed IP as the changes are infrequent.
As soon as I saw the non-delivery notices, I immediately checked my IP/DNS and, sure enough, my ISP had changed my IP address.
It took only a few minutes to fix it. Instead of buying a static IP address, I will regularly send a test email from my domain email to one of the emails I have on Outlook or Google.
My ISP charges AUD$10 per month for a static IP address. I’ll consider paying for this service if changes occur more frequently than just once in a blue moon.