ContentByMail is a plugin for Joomla which makes it possible to create articles by sending an email. In the simplest form the content of that message will be published directly, but there are also commands available by which the processing can be controlled and (nearly) everything that the regular user-interfaces enables you to control can also be controlled with these commands used in the email.
Using CBM you can manage your site's content without using the Admin-Backend. That is a relevant option,when the web-connection is not reliable / unstable - or when you prefer to prepare content offline in a maileditor and then have it published. CBM offers many features to control publishing, automagically embed attachments. It gives the admin full control over the content and also protects against attacks such as SQL-Injection or cross-Site Scripting.
You may use the sandbox to see how easy it really is to generate content for a website!