I lost a few couples of minutes trying to figure out where and how
rss2mail is storing its configuration
files, as I did not find in the documentation.
rss2mail is a couple of Python scripts to parse an RSS feed and send new items to an email address. It is really convenient but configuring it to have HTML instead of plain text and to choose police is really better.
On Debian, after
r2e new firstname.lastname@example.org, you should be able to edit the file
2020 update: I updated the address to Github as allthingsrss website is now down.