[Mailman-Users] Treat post from non-member mail addresses like join request?

[Markus]

Hi,

this is roughly what I want to achieve, with a list that allows posts
from members only:

- when a member mails to <list>@<domain>, the message should be posted
as usual

- when a non-member mails to <list>@<domain>, this should be treated
like a subscription request, i.e. as if he had mailed to
<list>-join@<domain>

I could not figure out how this could be achieved, and now I wonder
whether it is so an unreasonable behaviour?

Sure I could reject the non-member mails and in the reply tell them that
another mail address must be used to join, but this would be more effort
and multiple addresses to communicate.

Ideally, the initial submission would be held until the sender address
is confirmed and then posted to the list.

I have even thought of copying all mails to "post" and "join", but then
legitimate posts would get a reply "you are already subscribed" for
which I found no switch to suppress.

Regards
Markus