Automatically selecting the wrong wireless network can cause e-mail problems

We had an interesting support phone call today from a customer who was having trouble sending and receiving e-mail. She was using a wireless connection today. She had also been using a wireless connection yesterday, and it had been working fine then. Before calling us she had tried restarting her computer (as we recommend for most e-mail problems), but that didn’t seem to fix the problem.

After doing a bit of diagnostics, it turned out that the problem was that her computer had selected a neighbor’s wireless network after she rebooted. This different network blocked the necessary e-mail ports, so she couldn’t do e-mail. None of this was obvious until we started examining her IP address. She solved the problem by plugging her computer into a wired Ethernet port on her router, rather than using the wireless connection. When she did this, she got a new IP address which belonged to a completely different network, and suddenly she could do e-mail again!

So if you are having intermittent wireless network problems, be sure to check which wireless network your computer is connecting to. Choosing the wrong network can cause problems for e-mail and (potentially) for other services too.

We offer a web page which displays your IP address and host name. The final part of your host name is the network which are you using to connect to the Internet. For example, if your host name is c-71-205-218-196.hsd1.ca.comcast.net, then you are connecting to the Internet via Comcast.