Opt-In Pro is one of the perl driven modules that offers facilities to maintain the subscriber contact lists on perl websites. This allows website owners to create unlimited mail lists for their users who want to be a email subscription member. Double opt in form enables to remove fake users. Visitors can decide themselves to be a subscriber or non subscriber. Webmaster can send bulk mails to all members using a single interface with few clicks. MySQL or plain text file can be used as backend database.