I use Firefox as my primary web browser. One of the extensions I use is Gmail Manager, which checks my Gmail accounts) and tells me when I have new emails waiting. Here’s what it looks like in use:
A few days ago, I noticed that I wasn’t getting any new emails. I receive a ton of email, so this was unusual. I logged into my Gmail account to find I had about 25 new emails waiting. Gmail Manager obviously wasn’t reporting correctly.
I’ll spare you the troubleshooting steps I went through. Suffice it to say I spent a couple of hours looking into this problem, and I was not the only person experiencing this problem.
My research led to one, and only one, potential solution. There’s a service that every internet-connected computer uses called DNS – Domain Name Service. See, computers don’t understand terms like www.gmail.com, they understand numbers. The website www.gmail.com resolves to 74.125.47.17. Now, any DNS server on the planet can resolve this address, and my computer was resolving it just fine.
Every ISP from AOL to Comcast to Mindspring provides DNS servers to their customers. The internet would not work without DNS.
However, there is also a free third-party DNS system called OpenDNS. You can manually tell your computer to use their servers rather than your ISPs servers. When I set my computer to use OpenDNS, Gmail Manager started working again.
This makes no sense at all. My computer resolved www.gmail.com to 74.125.47.17 both with and without OpenDNS. The DNS server I use should have no effect whatsoever on any service that uses it – yet, here it is.
The first rule of troubleshooting is to look for repeatability. To that end, I went back to my ISP’s DNS servers and sure enough, Gmail Manager broke again. I checked this on two other computers. Same result.
I can’t come close to explaining this, and I’ve worked with Microsoft Windows for over fifteen years.