This version of procmail supports Maildir folders. To make procmail to deliver into a Maildir folder, just append a slash (/) to the name of the maildir folder in your ~/.procmailrc file. For example, the following rule: :0 * ^List-Id:.*debian-user.lists.debian.org debian-user/ will deliver all mail from the debian-user mailing list to the Maildir folder "debian-user".