Adding current users/ subscribers to mail list

Have upgraded my site to DP RT 6.5.7. Apart from a few issues I am almost happy it is fully functional.

I now need to inform all my current registered users of the changes and what it means to their listings (e.g. listing enhancements etc.).

However unlike V7, I do not see a way to send to all users through the new email manager.

If it is a case of importing all users and adding them to my mailing list, how can this be done?

Would appreciate any input as it is vital all users are informed of changes and new listing packages.

Thanks in advance.