The netrc.el file below contains a few functions from Gnus, making it
possible for smtpmail.el (and several third party packages) to use the
same ~/.netrc interface for storing passwords for emacs applications.
The patch for smtpmail.el to make use of it is being worked on.  It
would be a (better) alternative than to store the password in the
`smtpmail-auth-credentials' variable which might be stored in publicly
readable ~/.emacs.  Is it OK to add this?  (If so, could someone
commit it, lisp/net seems most appropriate.)