Securing Postfix.

[Patrick]

It is pretty secure by default. Check to see if you have added any 
domains/IP networks  as local.

Check any changes you have made to the main.cf also check to see if you 
are calling anything from another file that may have a command secretly 
snuck in them.

in particular mydomain/mydestination these should not affect relaying 
since it thinks it is these domains.

but then you have a section called Trust & Relay Control make sure you 
don't trust outside machines/nets.

Perhaps you have a hacked box or weak POP before SMTP/SMTP auth setup.

I suggest using the ISP's mail server for sending mail if you have 
remote users. Then you can control your local net. Check the logs 
perhaps you have a hijacked PC inside your network

ismgr wrote:

> Can anyone give me some pointers/feedback on the best way to do this?
>
> I have this box (Yellow Dog 3.0) setup and it is relaying mail 
> outside, but I want to make sure that this is kept secure.
>
> I've read through docs before on the main.cf file, and I think that I 
> have it configured right, but wanted to make sure that I'm not leaving 
> anything open from the outside.
>
> Thanks!
>
> Chris