Are there any Database functions which allow access to other network services in PostgreSQL I have set up a new postgres installation and have to meet the security requirements from my company.
There is one requirement were i'm not quite sure:

Database functions which allow access to other network services (e.g. ,SMTP, HTTP, SNMP, FTP etc.), must be deleted or deactivated.
Motivation: Some database systems provide functions that are normally offered by an application server. For instance it is possible via special stored procedures to send e-mails or launch web queries to external systems.

I have installed postgres (PostgreSQL) 9.3.4. Are there any functions like this in a standard installation on Red Hat Enterprise Linux Server release 6.5 (Santiago)?
I have never seen that personally, so I looked up all the functions in Postgres found in the docs here.

The only thing it showed remotely close was 'network address functions' in this section.  Outside of that the docs don't show anything for network access functions.  Note this doesn't mean you can't write your own functions that access the system or OS which then can access the network.