The California State Senate has passed a bill that would turn spam into a more serious criminal offence and cost spammers an estimated $500 (£304) per unsolicited e-mail sent.
Bill SB 12, was introduced because previous legislation has had little effect on combating unwanted e-mail.
A spokeswoman said the exisiting antispam law sets up an "opt-out" model, by which spammers are able to send unwanted e-mail until asked to stop. However, she explained that responding to spam through the opt-out model only verifies a live e-mail address.
SB 12 presents an "opt-in" requirement, whereby spammers must have permission before sending e-mail if they do not already have a business relationship with the recipient.
The "opt-in" model is based on a federal law that bans unsolicited or junk faxes because of the cost-shift associated with junk fax.
The costs associated with spam from the recipient side - such as ISPs raising access fees to pay for e-mail management, blocking and filtering; and businesses having to hire extra IT staff, purchase filtering software and deal with employee productivity loss - are enough to mirror the federal junk fax law, which allows consumers to sue fax spammers for $500 per fax.
Other states have also recently taken action against the rise in spam. Virginia enacted a law in April, which followed California's existing "opt-out" methods, but also made spam a criminal offence.
If California passes the law enforcing the "opt-in" method, it will send a strong antispam message both to US congress and to other states to go further than exisiting laws.
Carly Suppa writes for IDG News Service