Comment 29 for bug 42947

I just ran into this on a fresh install of 11.04. I think it may be because in the installation of postfix I selected "No configuration" from the configuration menu. Previously, doing the identical installation and selecting "Local only" I didn't get the error. And after removing and reinstalling postfix (as shown above), but this time selecting "Local only", I no longer get the error. I think "No configuration" is just not a good choice, because then the lack of a configuration produces errors.