How to send a mass mail?

how do I send mail to my members all at the same time?

We dont' have a feature like that today, because it would get abused...eg, a spammer might use it to send junk to a lot of members

You can always use your sent mail box to copy / paste what you've sent & resend it to more people that way...or setup a group & invite the people you want to join, etc. You can even set it private if you don't want everybody to be able to read it.