Majordomo restrict_post

[DCT Jared Smith]

This list uses majordomo software.
MajorCool is a web interface to Majordomo.

http://www.greatcircle.com/majordomo/majordomo-faq.html#3.13

3.13 - How can I stop people from using my mailing list to spam my 
subscribers?

[From mcr at solidum.com (Michael Richardson) ]
There are two approaches to solving spam. They are complementary.
The most general solution is to make sure that your list host will 
not accept spam. See http://spam.abuse.net/ for extensive recipes on 
this.

The majordomo specific way is to use the "restrict_post" mechanism to 
disallow posts from addresses that are not on the list. Please see 
section 3.6 for some of the pitfalls of using restrict_post. They all 
apply. My experience is that spammers have not yet learnt about the 
"-outgoing" alias, and the techniques in section 3.6 would apply when 
they do.

The major objection to using restrict_post to deflect spam is that it 
may deflect posts from legitimate people -- people who've subscribed 
with one address but are posting from another address. It may also 
restrict cross-posts from other lists, or from people who read the 
list via news.

The solution to the above objections is twofold: 

the moderator must forward legitimate posts. This can be a pain, but 
it does work. 

the restrict_post header can be extended. 
The typical way to do #2 is to set restrict_post to: 
mylist:mylist-nomail

Then, create a configuration file and password for "mylist-nomail", 
but DO NOT create any aliases. (If you use something like 
mj_build_aliases, then don't set the owner)
The moderator, or subscribers may then subscribe themselves to this 
second list. Subscribers to the -nomail list will then be allowed to 
post to the first list, but won't receive duplicate copies of the 
first list.