This plugin prevents people from registering with disposable email addresses (dea) like the ones provided by mailinator (also known as throw-away email, one-time email). It protects your most important asset, your registered user base, by preventing contamination by fake accounts. This plugin working principle is similar to spam blacklists.
It hooks in the wordpress function is_email() so it will extend the known email validation of wordpress to detect dea domains.
The plugin itself does not contain a list of domains to block. Instead of local maintenance the plugin uses the service of http://www.block-disposable-email.com. This is a very accurate free service for up to 200 queries a month. For huge sites several commercial plans are available.
Please see the FAQ section for some more information.