Bounce handling

["Stephane Rozes" <Stephane . Rozes @ Cert-Ist . com>]

Hi,

Sorry, it's my first post to the list and I didn't find any response to my
question in the mailing list archives.

I have a closed mailing where only authorized users can post to the list.
Sometimes I have some unauthorized users who try to post in the list. I
received the "bounce" message but I would like that the unauthorized user
received a customized error message as well.

Do you have an idea to perform this action ?

Thank you

Stéphane Rozes