A Birmingham expert has expressed doubts about proposals to charge a nominal fee for emails.
The idea has been put forward by AOL and Yahoo, who believe that charging a fee will reduce unsolicited mail and discourage spammers.
But Odette Beattie, head of marketing for Managed Enterprise Technologies, a Birmingham-based provider of managed IT services, believes that paid-for email simply won't take off.
"First, service providers are unlikely to be able to devise a system that can be guaranteed to distinguish between paid-for email and spam," she said.
"From our experience of working with many leading managed service filter companies, the technology available now will continue to block paid-for emails as spam.
"Second, a two-tier email system will be created - like first and second class post - with non-payers forced to wait longer for their messages.
"With the potential problem of AOL and Yahoo being unable to guarantee that paid-for emails won't be mistaken for spam, legitimate correspondence could end up at the end of a very long queue.
"This will lead to a potential divide in the market place between those who can afford paid-for email and those who cannot - and result in marketing departments in larger companies gaining a competitive advantage over smaller ones with lesser budgets.
"And yet the whole point of e-stamps, according to AOL and Yahoo, is to combat spammers.
"I'm not entirely convinced that it will. I believe that spammers will continue to send unsolicited email messages on the unpaid system because their results will not always hinge on time of delivery.
"This will surely result in longer queues and related problems for the providers, who will be faced with extra work in filtering messages and collecting fees, with inevitable cost consequences."
She added: "I would estimate the initial costs for this service to be around 0.5 pence per email.
"But you cannot put a price on the added headache of administration and paperwork. Like the regular stamps we all know and love, a fixed price is not guaranteed.
"Although the cost may begin at a nominal price, it could rise over the years to a prohibitive 5 pence, further shackling smaller businesses.
"By introducing estamps, service providers are playing with the boundaries of net neutrality.
"Instead of charging businesses, I believe AOL and Yahoo should invest more money in technology and managed services in order to reach their 'nospammer' goals. Companies such as Messagelabs and Mimecast have the technology now to help combat unsolicited email.
"But one can't help but wonder where it will end. Charging private individuals to send email? Privatising the internet? Are estamps just the thin edge of the wedge?"