Mailing list for Private Messages?

[Jesus Chio]

I need to create mailing lists but instead of sending emails, send Private Messages.

This to:

- Announce to sponsors/vendors
- Send announcements to moderators
- Allow communication amongst certain user groups (without revealing email addresses)

Could be user group mailing address, ie:

Moderators Mailing address: Sends a PM to all the moderators

Or custom designed, ie user 1, 33, 12111, and so on.

Thanks for your help!!