> I think there's some sort of preference setting in Entourage that may
> trigger that sort of problem. The same list has other Entourage users
> and they don't have this problem as far as I know.

I don't have the Entourage experience, but I'm hoping this data will help if
anyone on this list does know the product.

> Here's the header of a recent message ...
    :
> Reply-To:   [log in to unmask], [log in to unmask]

This looks well-formed to me. I don't see why it should mess up the replies.

However, I do notice that the sample you sent originally shows the replies
going to:

  "Macintosh Users Group of Southern NJ , Stan Horwitz"
  <[log in to unmask]@TEMPLE.EDU>

when there is a problem. The interesting thing here is that the Reply-To:
header entry does not supply the names associated with the addresses; it has
only the addresses themselves.

That means there are two possible causes: either Entourage has a
configuration option somewhere that causes it to mess up if set a particular
way, or Entourage processes the addresses differently (and messes up) when
it finds matching address-book entries and tries to add the names.

I have delayed sending this while trying to come up with an example of a
two-address Reply-To: field, just to see if my own email client (Microsoft
Outlook Express) can understand it. So far, I have been unable to get OE to
send a well-formed two-address field in the first place.

Hal Keen