Kolab 3.1 postfix relay access denied

[Herwig Unterrichter]

Hi Tom,

to permit authenticated users you need to edit /etc/postfix/main.cf,
and add "permit_sasl_authenticated" under variable 
smtpd_recipient_restrictions.

cheers,
Herwig

---
Herwig Unterrichter
bitArk technology e.U.
www.bitark.at


-------- Original Message --------
Subject: Kolab 3.1 postfix relay access denied
Date: Mon, 17 Mar 2014 19:56:28 +0100
 From: Tomas Kucera <tku at centrum.cz>
To: <users at lists.kolab.org>

Hi there,

I would like to ask for a help. I am not at all proficient in postfix. I 
got to a point where it seems like a lot of things work as expected. The 
current thing I am fighting is the following:

- CentOS 6.5
- Kolab 3.1 (tried 3.2 but the multidomain setup just did not work)
- multidomain setup
- from Roundcube everything works fine
- from external client (in my case Mail on Mac) when sending an email to 
a domain that is outside of the domains under control of Kolab / postfix 
I get Relay access denied.

I suppose that it is correct with the default setting but I just cannot 
figure out how to configure the postfix in a way that it will accept 
authenticated users and will allow them to send the emails everywhere.

I went through the documentation of postfix and tried some of the 
options for smtpd_xxx_restrictions, but did not get it to work.

So, please, please, help me!!!

A bonus would be to give some hints on potential security threats.

Thanks in advance!

Kind Regards,
Tom.