[Pkg-exim4-users] Allowing SMTP from localhost only

[Peter Bittner]

Hi there!

I have Debian Sarge with exim4 set up for "local delivery only". The
installation is up-to-date, all packages are updated/upgraded.

Now, a web application I am running on my machine needs to be able to send
authentification and reminder mails, so I need to modify this config
slightly to allow delivery of mail to remote hosts. For security purposes,
however, I want this to be allowed from localhost only!

I have skimmed through the configuration file(s) and the documentation. I
think I understand the way the Debian exim4 setup works, but I'm still not
sure how to achieve the type of configuration I need.

The preferred way to go for me would be adding some line(s)
to /etc/exim4/update-exim4.conf.conf, but I fear that won't suffice. I
probably need to modify /etc/exim4/exim4.conf.template directly.

But then still: What is the correct setup?
(I see "local_interfaces = 127.0.0.1" is already
in /var/lib/exim4/config.autogenerated, but send mail doesn't work.)

Can someone give me some hints?
Cheers, Peter