Who Needs the Web?

Members of the ISP-Tech list discuss the nuts and bolts—and the viability—of offering cheap e-mail only accounts.

[December 3, 2001]

On the ISP-Tech list in November, NN queried,

"I'm interested in starting up a service that will allow dialup users e-mail access only, with no links to the Web allowed in the e-mail. Does anyone have advice on how to set up something like this?"

Some respondents offered suggestions on how to block Web access:

[BS advised] "Firewall them out of everything but ports 25 (SMTP) and 110 (POP3) on your mail server."

[PT added] "And 53 (DNS) as well."

[DS noted] "This is easy to do for Livingston users. For our filtered Internet customers, we have a group set up in RADIUS that tells the PortMaster to apply a filter which blocks port 80. It could just as easily block other ports, leaving only 25, 110, and 53."

[MD suggested] "A simpler way to do it would be to assign non-routable IP addresses to customers and not let them outside your network. And for URLs in messages, write a wrapper around sendmail's local delivery agent to strip URLs out of content based on the destination username."

[DC added] "If the ports for e-mail are the only thing allowed for the connection, the URLs will be of no benefit to the user; they will just time out. I think the difficult part might be to set up the account access rights. If these users are on the same network as normal users, then the system has to assign the proper rights to an e-mail or normal user account based on their login info."

Others disagreed about the commercial viability of such a service:

[JM asked] "What's the point? It wouldn't be much of a service if someone sends me a message with a link to some important information and your system has removed the URL. Besides, a lot of ISPs offer, for just a few dollars per month, Internet dialup with a very low limit on the number of connection hours. This is essentially the same thing with Internet included, as the people using these accounts are only interested in e-mail."

[RS countered] "An e-mail only service might be a very good niche. Think about it: if customers only retrieved e-mail, they would be online for a very short time. You could charge much less, and run a much higher user to modem ratio. I bet the numbers would work out to increase profit. Also, those customers that only need e-mail would be attracted based on the lower cost. In these days of high bandwidth and competition from so many directions, it might be an incredible idea."

—End