What is the most simple MTA to use and configure on Debian 6 squeeze, with dkim filters?
I would like to only send mail from it, not receive. Google apps handles my inbound email.
Postfix and Opendkim is quite simple to set up.
You probably want SMTP auth too, but that is also very simple with postfix.
Alternatively, exim 4.72, as packaged for Debian Squeeze, has DKIM support built in. It's not quite as straightforward to configure as Postfix, but if you use the Debian 'split config', it's fairly understandable, and the recently revamped documentation is good.