Postfix supports the use of a catchall account using the luser_relay configuration option.
See the postfix page for luser_relay for more information.
When the local(8) delivery agent finds
that a message recipient does not
exist, the message is normally
returned to the sender ("user
unknown"). Sometimes it is desirable
to forward mail for non-existing
recipients to another machine. For
this purpose you can specify an
alternative destination with the
luser_relay configuration parameter.
If it is not a catchall for all domains on the server you can instead user Virtual Aliases. See the postfix page for virtual aliases for more information. Short description and code excerpt from that page are as follows:
With virtual alias domains, each
hosted address is aliased to a local
UNIX system account or to a remote
address. The example below shows how
to use this mechanism for the
virtual_alias_domains = example.com ...other hosted domains...
virtual_alias_maps = hash:/etc/postfix/virtual
# Uncomment entry below to implement a catch-all address
...virtual aliases for more domains...
After making those changes, run
postmap /etc/postfix/virtual and
EDIT: I think the regexp that you are looking for is
You might need to make additional changes in main.cf to support this. See this post for more information.