Simply place a check-mark in all the categories of Members you wish to send mail to, and optionally select a Country - eg : if you wanted to mail all the members in a certain category in the UK, you must select both the Category of Members you wish to mail and also the Country (UK) from the drop down menu.

Once you have selected a list , click on the 'Create List and Enter Message' button at the bottom of the screen.

You will be asked to enter a Subject and Message.

Then click 'Send Message' at the bottom of the screen

The message is sent to everybody in the list you selected.