Internet connectivity issues are not reported to the user and instead are given network related issues. For example, you do not have an active WiFi connection, try to access a site, and get a DNS error. This leads to us misdiagnosing the problem to the user. We do have the capabilities to do connectivity detection, however the feature is disabled due to the implementation not behaving how we want. In addition, there were cases where users would be stuck in “work offline” mode. See attached URL for a full discussion and potential solution to the problem. In a nutshell, we should decouple "work offline mode" and internet connectivity state so that the scenarios outlined in the full discussion do not occur. The designs outlined in bug 966115 assume these changes take place.

Note: This is part of a larger offline/disconnected cleanup project outlined here: http://people.mozilla.org/~vtsatskin//notes/Projects/Message%20Cleanup/proposed.design

I'm doing parts of this in bug 939318

The referenced URL with suggested design no longer works. Perhaps the contents could be attached here instead?