[Mailman-Users] Spam filters and non-member posts

[Daniel D Jones]

I've been running a private list for several years with Mailman configured to 
reject posts from non-members without any issues.  Recently, however, I've 
been getting spam with forged headers which purports to be from me.  Since I'm 
a member of the list, they're allowed through.  To deal with this, I added 
some regex's to look for the SpamAssassin spam headers and to hold any message 
that appears to be spam.  This is working except that I'm now getting a ton of 
holds because Mailman appears to be checking the spam rules before it checks 
the sender rule.

I'd like all posts from non-members discarded and posts from members to be 
spam checked and held if they appear to be spam.  Is this possible without 
hacking the source code?