Dantowitz Consulting & Research, Inc. produces MailBurst (originally known as (DC&R Util 5), which handles multiple (virtual) domains under the Eudora Internet Mail Server (EIMS) and Stalker Internet Mail Server (SIMS), as well as providing intelligent email routing.
Can't find what you're looking for? Try a search:
Also, if you have an older Mac, be sure to check out the "Classic" applications page for more options.
Finally, take a look at ALEMIA if you think you know that name of an application, but aren't quite sure.
No, I don't accept reviews anymore for these older applications. With the creation of this page in the Orchard's late 2005 redesign, I only accept reviews for currently-developed applications that work on Mac OS X (or later....whatever that might be!!).