At first glance, Doorman may appear to be a typical way to send and receive e-mail messages from the mobile handset. However, Doorman is far from typical in terms of its "natural usablility", and its ability to protect all network users — even those who do not use e-mail features from spam make it a truly unique product.
Anti-Spam: Doorman uses a variety of predictive anti-spam heuristics designed to around requirements particular to mobile carriers. Spam is analyzed for content, delivery patterns, origin, previously-seen information, and much more. Carrier-oriented anti-spam heuristcs include protection against carpet-bombing attacks, and false-positive protection aware of SMS alerting and dispatch services.
Doorman anti-spam covers all users of a carrier's E-mail-to-SMS domain for a fixed cost.
Monetization of E-mail: Doorman affords the mobile operator previously unrealized opportunities to monitize E-mail-to-SMS service. Doorman can prompt users with a read-confirmation message ("You have mail from email@example.com - would you like to read it?"), which also provides the opportunity to create tiered features, and hence, additional line items on subscriber's bills.
Thus, with Doorman, carriers have the opportunity to take a loss-leader service and turn it into a opportunity yielding both SMS MO bucket and line item billing opportunities.
E-mail-to-SMS: With Doorman, e-mail messages are not simply delivered to the handset are unsightly globs of text. Message formatting is preserved, HTML (rich text) e-mail messages are converted in a reasonable way, subject lines are preserved, word processor attachements are converted to text, and much more. Additionally, messages can be paged through with the "more" command to see more than just the first 160 characters of the message, and replies can be sent back to all message recipients — just like any well-behaved e-mail client.
Intuitive Interface: The Doorman application uses a context- and input-sensitive interface. This means, for example, if a user send a text message in response to an e-mail message, that the user's response will be turned into a reply to the e-mail message. There is no need to explicitly tell Doorman the destination e-mail adddress for each message. A natural interface also means fewer problems for mobille operator CSRs to diagnose. For example, if a user who was provisioned as an anglophone suddenly starts using the service with French commands, Doorman will answer back in French. But once the user starts speaking English again, Doorman will happily switch back to english.
Completely Self-Provisioned: The Doorman user interface allows 100% provisioning and configuration from the mobile handset, without interaction from the wireless carrier or even the carrier's provisioning systems. Users can sign up, quit using the service, configure personal parameters, and much more, but sending simple messages back to a designated "adminstrative short code".
Even in cases where users are not familiar with Doorman, Doorman will prompt them to subscribe when they have new messages waiting.
Value Added Features: Doorman allows users to configure several parameters of their accounts, such as vanity e-mail addresses (aliases), first and last name display, e-mail signatures and so on.
Doorman also allows users to manage allow and deny lists for correspondents, giving users control over e-mail traffic received on their cellular handsets.