For Sprint and Nextel cellular phone customers, a basic cellular e-mail client software package is now being added to the regular tier of service at no additional charge, for select phones capable of sending text.

The move comes as competitors Verizon Wireless and Cingular continue to work toward providing similar software to consumers, but for a monthly fee.

Sprint's client system provider will be SEVEN, which is already a provider of some services for Sprint, as well as for Verizon Wireless and Cingular. Though SEVEN does manage its own enterprise e-mail servers, it leases that service to businesses for a fee, as does BlackBerry and Good Technology. For its consumer-level alternative, however, SEVEN provides the client software with a "BYOS" (server) plan that enables you to connect with your existing, mass-market provider.

This saves the carrier from having to invest in servers whose upkeep and oversight costs would have to recouped somehow. If consumers are being charged zero, those costs would have to be shuffled over to the higher-tier customers, whose BlackBerry or Good service fees must be kept low to stay competitive.

Consumers who opt into Sprint's new service can download the SEVEN client software directly to their phones, according to SEVEN, either over the air or through a computer connection. Sprint's move to zero-cost may provoke responses soon from its competitors who currently offer SEVEN clients for a monthly upgrade fee.

Though precisely which SEVEN client software Sprint has chosen has not officially been announced (BetaNews has requested clarification from Sprint on this issue), existing versions already in the field rely on computer software called a desktop redirector. This software collects e-mail from multiple sources on the computer, and then re-sends each item back through the Internet, to SEVEN's network. From there, it's streamed directly into the phone, so that the customer need not bother with setting up multiple accounts through the cumbersome phone console.

The problem with this system, critics point out, is that it requires the user's computer to be continually active, in order for her e-mail to be active as well. This means the computer must be left on, which in some businesses and even households isn't always possible.

But the SEVEN system does have an advantage over one alternative from Verizon, as one reviewer discovered last July: In Verizon's Wireless Sync scheme, Motorola Q phones maintain a continual Microsoft Exchange connection with Verizon's mail servers, where both messages and contacts are stored...perpetually. In other words, rather than performing direct synchronization with the mobile device, as SEVEN's products do, Verizon's alternative collects the e-mail components from all customers' other servers into a single repository. This could be a problem when the carrier cannot guarantee the data security of the repository - a problem which the SEVEN system doesn't have.

Sprint's service may not be entirely free of charge. For Sprint users to receive synchronized e-mail -- in other words, to receive e-mail directly on the phone just after it's received by the redirector on the PC, and to be notified immediately -- standard text messaging rates will apply. If your regular e-mail inbox tends to get very full, very quickly -- for instance, with newsletters -- Sprint might not have to worry about missing those monthly fees for awhile.