how to send login infos to all web users

Hello !

I’ve made a website for an association with 20 webusers. I want to send a general email to inform them of their personnal login and password.
I tried the "message" button in the top of the manager, and send me a message, but it didn’t work !

In the configuration there are predefined messages for this. but how to use them ?

Members must pay to access to private pages, so I can’t use websignup snippet


Thanks a lot

Amigafreak