Web Party Time's group e-mailing tool provides you with a way to send announcements or updates to a group of email addresses at once. Each recipient will receive a unique email from your email account with no other recipients listed (instead of being on a CC or BCC line). 

This was created to be used for our virtual event websites so hosts can easily contact their entire guest list. It was not built for large-scale commercial use and may not suit the needs of your organization as such.