Hello, I'm trying to ban @aol.com for signing up to wikimediacz-l. This is a member-only list for Wikimedia Czech Republic members and as aol.com is pretty unfrequent in Czechia, I don't expect any problems (and if there will be some, members of the list are added by a list administrator). There is a big sign-up spam, so that's the reason why I decided to issue the block. If there is a way how to enforce manual adding by a list administrator, I'll be happy, but helping how to add whole aol.com to ban_list will be useful. I tried to add "^.*(a)aol.com$" (a regex) to the ban_list variable, but this apparently do not help, still some aol addresses are able to sign up. Thank you in advance for any help. Martin