creating mailing list in php?

Hi y'all. I am working on a mail list app that's pretty simple...don't need to let users post, only admins, and it's very straightforward. I tested it out with mail() on 50 addresses, and it took 78 seconds plus massive server load. Part of that may be the mail scanner we have, but I also know mail() opens a socket each time, and that's gonna make it pretty slow too. Does anyone have any suggestions, or even examples of what you've done for this type of thing? The load is about 3000 emails daily, all at once (the client emails out daily specials to their clients), which at this rate would take over an hour to send. Also, and I might just not be paying attention, but is there any word about this list going phpBB or the like sometime soon? That would be great. Thanks again for your help. -jason