By Vivek Bhatia

One of the unseen-and unfelt-side-effects of the Net on language, I feel, must be the virtual extinction of the economist's song: There's no such thing as a free lunch. Take free e-mail, for instance. When it appeared, the most common reactions were: ''It will never be viable.'' ''There must be a catch.'' ''It's just a short-lived gimmick.'' Well, the good news is that all three are wrong.

Free e-mail-more correctly, advertising-supported e-mail-is here to stay as a Net service. Worldwide, around six million people are using free e-mail, and there is now enough competition for the free e-mail providers to be working hard on service and interface issues. And free e-mail is specially important in India where, typically, a large number of people in an office share a single vsnl Net account. So, here's my pick of the free e-mail service providers:

HOTMAIL http://www.hotmail.com: With a 14-month track-record, and 5.50 million users, this site is probably correct in claiming to be the first-and the largest-free e-mail service. Its extremely-usable interface is completely intuitive. Moreover, Hotmail scales effortlessly from being a simple-to-use service to the power-user's delight. You can set up any number of folders but, more importantly, you can set up automatic filtering. Based on some conditions you define, such as subject and sender, Hotmail will automatically transfer the mail into a designated folder-or even forward it or delete it.

ROCKETMAIL http://www.rocketmail.com: Rocketmail is the hidden ace in this pack. It has everything that Hotmail has-and some more. The interface is less slick than Hotmail, but is generally faster since it uses less graphics. Rocketmail is more generous than others with things like hard-disk space for your mailbox too.

MAIL CITY http:// www.mailcity.com: Mail City is new. So, its track-record isn't known, but it is the fastest of the free e-mail services on the Net. Being a late-comer, Mail City is the most lavish: it is the only free e-mail service with no limits on mailbox size or mail attachment size. It also has an answering-machine-like system by which you can set a fixed reply to be sent to every message while you are on a vacation and unable to check your mail.

There are more me-too services like Mail Excite http:// www.mailexcite.com and NetAddress http://www.netaddress.usa.net. But the real news is that the Net search giant, Yahoo!, is getting into the business. If the Net is to be believed, by the time you read this, Yahoo! is likely to have bought Hotmail. Or, at least, signed a joint venture with it. And, with its 35 million-a-day visitor population, Yahoo! could well transform free mail into the standard way to access e-mail.