jvstratum Hello,
I am using version 6 of AcyMailing for Joomla!.
I am having the same issue -- certain domains still signing up for the newsletter, even though I have blocked them in Joomla user registration.
The links you provided only open a menu in the documentation, but I don't see where to go from there. :-\
Please post the auto-filter instructions/steps needed to handle this task, here in the forum.
Many thanks!