Isn't it easier to use mod_block_strangers module (introduced in recent versions)? At least currently, spammers are not yet able to bypass it.
Actually no. 1) Module does not work correctly as it pointed. 2) Spammers are sending now Presence subscription request. -- Rafal bluszcz Zawadzki - https://bluszcz.net https://jabberpl.org - 15 years old XMPP server which does respect your privacy.
