It would be nice to have a mail address to send messages to that are then 'automagically' added to a Trello list on a specified board. So it could be used for some sort of issue tracking.
Is it / will it be possible somehow?
Yes this is possible with a tool like Emello.
Send your email straight to Trello with Emello. You get dedicated custom email addresses for each of your Trello boards. Start sending email to Trello today.
This is now a feature in trello. Just click on "Email-to-board Settings".
I ended up using Gmail to Trello Chrome extension, working good and easy to use.