As a result, SMS and email will co-exist on the mobile phone much like email and instant messaging co-exist on the desktop.

MMS hasn't done very well in the consumer marketplace, so why will mobile email?
MMS (Multimedia Messaging Service), when marketed as "picture messaging" demonstrates little and/or sporadic value to consumers.

Maybe you want to send a picture from your phone while on vacation, but it's probably not a service you would depend on daily. In contrast, consumers already depend on email and use it everyday.

Mobile email gives consumers improved access to messages that matter and gives operators a great way to drive traffic over the MMS infrastructure they've already invested in.

Consumers aren't using smartphones
For the most part, consumers are not using smartphones, so the prospect of composing emails on a small cell phone keypad is not enticing.

Most consumers care more about receiving important emails on their phones than they do about sending them. In fact, research shows that consumers want to receive important emails while on the go, but they will typically respond to only 10 to 30 percent of them by typing a reply message the phone. Instead, many will respond by voice -- generating more voice traffic and additional revenue for carriers.

Final analysis
According to the U.S. Mobile Market: trends and forecasts 2005-2010 report from Analysys, wireless messaging revenue in the U.S. increased by 106 percent in 2004 and is expected to continue to grow strongly over the next five years. By 2008, wireless messaging alone will account for 10 percent ($16.4 billion in U.S. dollars) of operators' total mobile services revenue. We believe the consumer mobile email market represents a significant portion of this growing revenue opportunity.

To capitalize on this opportunity, carriers need to think beyond the enterprise to the mass market. But first, they must take a step back to really see what consumers want, how they want it and how much they want to pay for it. Consumers want only the messages that matter to them, at a price they can afford, that works with their existing technology. And the carriers who understand this, listen to what consumers are saying and deliver services efficiently will reap the biggest rewards.

Mike Serbinis is CTO of Critical Path. Critical Path developed Memova Mobile, a solution for the mass market that pushes messages from the users' existing email accounts, such as Gmail or ISP email accounts, to their cell phones. Memova Mobile works on any MMS handset and allows users to select the email addresses they want to hear from.