[Mailman-Users] Mailman without localhost

[Kapuzino]

Hello 

Long time ago I asked, why Mailman delivers only to server-internal recipients. 
We found out, that the reason was the removed localhost from whitelist in plesk outbound filter. 
My hoster (I'm only custumer) could not bring to function the recommended solutions, either connecting to a new free port or to a port with authetication. 
He was doubtful to apply the patch, described in https://bugs.launchpad.net/mailman/+bug/558281 . 

Now I changed the hoster, but his Mailman works in the same manner. 
I suspect, every lowcoast hoster has configured his apache-plesk-package in the same way, I wil be the only one mailman.user, and the operator is not familar to that. 

Is there meanwhile an implementation of this patch in newer version, so an reinstallation of MM gives secure and easy adjustments for that case? 
Or a foolproof step by step instruction to fix it ? 

greats 
Kapuzino