Postfix setup: transport dependent address rewriting

Hi NG,

I am using:
- SuSE Linux 8.2
- Postfix: postfix-2.0.6-8

in the following setup
PC.LOCAL --WWW--> SMTP.ISP.COM.

I would like to setup the following behaviour:

1. All mails being delivered locally don't get their from-address rewritten
(All mails have pc.local / localhost as from-address)

2. All mail which cannot be delivered locally, have to be sent to the
smarthost (smtp.isp.com) with a rewritten eMail address (from - field)
(e.g. user@isp.com).

3. When I send a mail to an eMail adress without any domain (e.g. To:
user2), postfix should add @pc.local and deliver the mail locally.
I know, that I could set this up in my MUA, but I would like to have it in
the MTA, because it is easier to write scripts that way...

I tried to use the myorigin parameter, but this doesn't seem to be usable
for local mail, as a result of bad from-field.

I appreciate any help.

Robert Hilbrich