PHDEmailer has one job, and that's to let you know when your guiding has gone awry in PHD Guiding. We can't always be right by our imaging rig obsessing about our guiding; PHDEmailer does that for you and will send you an email alert when a pesky cloud jumps in front of your lens or when one of your imaging "buddies" decides to treat your mount like a piñata.
You can even set the "E-Mail Address" to be a SMS gateway so you'll receive a text message on your cell phone when things go awry!
PHDEMailer is free and can be found in the downloads section.
If you find PHDEmailer useful feel free to donate to keep awesome free applications like this coming!