I'm putting this out here without really testing it, since we typically don't modify our templates.

I assume the message that's got you in trouble is the one which reads "You are not authorized to send mail to the such-and-such list ..."

I found it by pulling down Server Administration -> Customization -> Mail Templates.

Then Select Template Category = Posting Responses

Then Select Template = [MSG_POSTING_REJECT_NOTAUTH]

Ron wrote:
>   I need an A, B, C, step by step guide.
> 
>   First of all, in the top menu I have,
> 
>   Server Administration, List Management,
> 
>   I'm sure it's got to be under one of these,
>   but which one?