In February 2006, AOL revealed that it would soon be taking payment for incoming emails in return for skipping its usual anti-spam filters. The payment system chosen was Goodmail's CertifiedEmail product, which features an individual email authentication system that enables AOL and Goodmail to charge a per-email fee to senders. The charge is estimated to be around a quarter of a cent per mail received.
When ISPs or mailbox providers demand a cut to allow mailers - even legitimate mailers - to bypass their filters, it creates a perverse incentive that impedes other efforts to improve bulk mail deliverability. Poorly functioning filters that reject or discard legitimate mass mail now become sources of revenue for the intermediary, instead of a liability. Future methods for ISPs of determining the legitimacy of incoming mail end up competing in terms of how much revenue they might provide instead of purely on their effectiveness.
Payment through certification poses a particular problem for free speech online as certification and authentication solutions, when used exclusively, can penalize anonymous free speech. Taking money from senders also divorces the aims of third-party mailbox handlers from the intentions of the end users: a recipe for further unintended consequences in the fight against spam.
