catfriend is a ruby program that checks your e-mail and creates desktop notifications using dbus. It can create notifications on all window managers that support the freedesktop notification specification including KDE, Gnome, Awesome.

• Can check multiple accounts.
• Uses IMAP IDLE to notify as soon as mail arrives rather than polling.
• Simple configuration file format.
• Updates an account's notification if it has not been closed rather than creating duplicate notifications.
• Supports IMAP accounts with or without SSL.
• Can be shut down using dbus (catfriend -s).
• Does not punish the fearless.

The fourth step is only necessary if you are using a mail-server with a self-signed SSL certificate. This is a security measure to protect you from spoofing.

$ gem install catfriend
$ cd ~/.config/catfriend
$ edit catfriend
$ wget http://location.to/ssl-public-key.pem
$ catfriend

The configuration file lives at ~/.config/catfriend. Here is an example config:

imap imap.gmail.com
    id        fun  # used instead of host in nofifications when available
    user      friend@gmail.com
    password  faptap
    cert_file server.pem  # relative to ~/.config or XDG config dir

imap insecure.work.com
    user      bossman@work.com
    password  insecure
    nossl # turn off ssl, it is on by default
    work  # mark as work account, -w command-line argument enables it

# Time notification remains on screen in milliseconds
notificationTimeout    10000

• Support POP3/Atom/RSS