The mailing list for listmasters using Sympa

["christopher pax" <address@concealed>]

hello sympa users.
I would like to completely disable list welcome message.
I am soon going to create a large list of all employees.
I do not want them to receive any welcome messages.
This includes any other type of message.
All i need here is assurance that it wont happen.

on another note,
i want to make sure that i can be safe from spoofing attacks.
I want only a few group of people to be able to post to the list.

with php, or some other tool, i can send a email
out to make the "from" field look like the person who
is allowed to post to the list (much like google is able
to send mail with a alias).
I dont want anyone to be able to do this. even google.
i would accept only allowing some on from a certian domain.
like, if i know the original IP is a subdomain of mydomain.com
i can allow it.