Density is defined as how thick or thin you want your hair to be. The standard and most popular choice is 130% which is Medium Density. You can see examples of the density - Click Here.
Google's Gmail Web-based email service runs on the Internet Message Access Protocol system, but it also offers Post Office Protocol mail server access.
Customize spam filter settings. This feature is not available in the legacy free edition of Google Apps. About approved senders. To customize spam filter settings. Incoming email messages are subjected to Google's spam filters, which automatically place messages detected as spam in a user's Gmail spam folder. Using the Spam setting, you can customize your organization's spam filters in the following ways: