I have installed httpmail 1.42 on OS X 10.3.7.
Randomly the messages stopped being displayed in my inbox. It
shows in the actions that the messages are being downloaded, but
they are not placed in my inbox.
I created a new account on my computer and did a fresh install of
httpmail on that account, and encountered the same issue. as
well, I have a second computer in which it is still working
correctly, and after copying the files in "user/mail" it still failed to
show the messages. So it is not localized to users, but appears to
change something system wide.