Richard H: How are you planning to use these quotes? If they're in a published work, there are formats to citing everything, including email and discussion lists. Someone sent me an essay to read recently, with several citations pointing to emails she had exchanged with the subject of her essay. I've modified them, and below you'll see a couple of forms you could follow. This first one looks like it's Modern Language Association (MLA) style.

Hawk, Little. "Re: Mudcat and Guests, a burning question: What to do with them." E-mail to the author. URL: http://www.mudcat.org/(etc.) 21 Sept. 2000.

Chicago Manual of style might do it like this (they want the author and date first, the order of the rest is a guess on my part):

Hawk, Little, 21 Sept. 2000. "Re: Mudcat and Guests, a burning question: What to do with them." E-mail to the author. URL: http://www.mudcat.org/(etc.).

Use Little Hawk's real name (aka Little Hawk).
SRS