When pressing the of offline/online button on Evolution's status bar, the "Do you want to synchronize" dialog comes up and offers a checkbox to disable this dialog in the future. If I choose to disable the dialog in the future and then choose "do not synchronize", then future clicks on the offline button will cause a synchronization.

I have a few issues with that behavior:
1. Its entirely not clear what Evolution will do in the future when you go offline and the "quick offline" prompt is disabled - the dialog is ambiguous about it at best and the user can easily surmise that Evolution will do the same action as was chosen in the prompt, which is obviously not the case.
2. The user has no way to revert the action if they decide that they do not want Evolution to synchronize every time they go offline. (I'm aware of the gconf key, but its hardly discoverable).
3. There is no way to go quickly offline (i.e. without synchronization) and without going through an interactive dialog. An interactive dialog is probably not the very definition of "quick".

This issue is also reported as Launchpad bug https://bugs.launchpad.net/ubuntu/+source/evolution/+bug/429008 .