[CentOS] Postfix won't relay after update to CentOS 4.4

[Feizhou]

> Anyway, I'm just glad it's all running again.  I'm even happier that it
> wasn't the postfix update that messed things up.

glad you have got things up and running again.

> 
>> the smtp daemons will run as postfix user and so sasl_passwd.db has to 
>> be readable by postfix user.
> 
> Actually, postfix starts as the root user, reads everything it needs to
> get going (including the sasl_passwd.db file), and then drops privileges
> to the postfix user.

Actually, master runs as root and it does not read everything and then 
drop privileges but continues running as root.

Try 'ps axuww|grep master'

Stilling running as root.

smtpd, smtp processes will be run as postfix user and they do not read 
everything to get going either. That why you can update tables without 
stopping and starting postfix and see the updates going live after a while.