Update README with notes about emails and sendalerts command.

README.md

@@ -63,6 +63,36 @@ in development environment.
 
         $ ./manage.py runserver
 
+## Sending Emails
+
+healthchecks must be able to send email messages, so it can send out login
+links and alerts to users. You will likely need to tweak email configuration
+before emails will work. healthchecks uses
+[djmail](http://bameda.github.io/djmail/) for sending emails asynchronously.
+Djmail is a BSD Licensed, simple and nonobstructive django email middleware.
+It can be configured to use any regular Django email backend behind the
+scenes. For example, the healthchecks.io site uses
+[django-ses-backend](https://github.com/piotrbulinski/django-ses-backend/)
+and the email configuration in `hc/local_settings.py` looks as follows:
+
+    DJMAIL_REAL_BACKEND = 'django_ses_backend.SESBackend'
+    AWS_SES_ACCESS_KEY_ID = "put-access-key-here"
+    AWS_SES_SECRET_ACCESS_KEY = "put-secret-access-key-here"
+    AWS_SES_REGION_NAME = 'us-east-1'
+    AWS_SES_REGION_ENDPOINT = 'email.us-east-1.amazonaws.com'
+
+## Sending Status Notifications
+
+healtchecks comes with a `sendalerts` management command, which continuously
+polls database for any checks changing state, and sends out notifications as
+needed. Within an activated virtualenv, you can manually run
+the `sendalerts` command like so:
+
+    $ ./manage.py sendalerts
+
+In a production setup, you will want to run this command from a process
+manager like [supervisor](http://supervisord.org/) or systemd.
+
 ## Integrations
 
 ### Pushover