Connections time out all the time. It would be helpful to many advanced users to have the ability to disable the alerts that pop up telling you that it happened. Usually it's fine the next time you try it. Some kind of icon that appears in the status bar to indicate an error occurred, that you could click to see the error message, would be more than adequate for most advanced users. Having the app stop fetching mail on all your accounts while it waits for you to click through this alert (which often opens behind other windows) is frustrating.
I would like to see non-modal notifications instead: http://www.stichpunkt.de/firefox/pics/popup1.png
Connection timeout alter would be bug 123440 I think.
Yes, this is a better idea.
Marking as dupe, then.