Fetchmail again - looks like a postfix issue.......SOLVED IN PART

[vincent at acheson.uk.com]

Haven't found an answer for fetching from a catch-all account using
fetchmail so postfix can parse intended addressee - such a course is
deprecated in the fetchmail manual, so am using one line per mailbox, with
each user having a separate mailbox at the isp end.

You MUST specify the local user, or delivery is attempted to
root at localhost.yourdomain.com, which will give rise to errors and
undelivered mail

Vincent