Dreamhost specifically has a "mailing list" feature (called "discussion lists"). These have no limit on the number of outgoing mails and give users the option to opt-out of the list.

You can create multiple such lists for different subjects (and there's an API for managing them in addition to the usual DH Panel controls)

If you are getting that many request today maybe a basic web interface should be on the top of the list of things to do. Besides it may be a better user interface to checkout project titles rather then read one gigantic email every day.

Thanks for sharing the problem here. I've just signed up and was wondering why I haven't received the e-mail.