This subject comes up periodically on all mailing lists and it is never resolved, so I doubt we shall resolve it here, either.
The course of least resistance for most of us is hitting the "Reply All" button, which does mean the original poster gets two copies. The diligent, considerate choice is to hit "Reply", then replace the original poster's address with that of the list.
Steve "diligent and considerate about half the time, harried, indignant, and boorishly inconsiderate the remainder" Freides
TW406@aol.com wrote:
>
> Yo dudes and others, no need to copy someone on the list with a personal
> email, cause then we get two, and sometimes this mail gets to be too much to
> wade through!
>
> Sincerely