Rather than using a combination of rules and filters, Microsoft's 'Snarf' will instead work out who matters most, writes Mary Branscombe

Swamped by e-mail? Marc Smith, Microsoft's research sociologist, assures you that you're not alone. "In our survey almost two-thirds of people admit e-mail has become a problem for them - as much a source of pain as it is a tool to help them."

He believes the way users handle messages makes a difference. His research found that people use two main techniques, which he calls "single pass" and "multi-pass".

Looking at each message just once and dealing with it - the basic principle of many time management systems - works better than trying to clear out the clutter by weeding out spam and those messages that can be dealt with quickly.

"The people who review messages multiple times are less satisfied with their e-mail experience; they're more overwhelmed. They feel they have to store messages for later because they can't deal with it all at once."

But simply getting smarter about the way you go through the inbox is not enough because even quick responses can often fail to cope with the sheer volume of messages.

"It takes maybe a minute to read a message and two minutes to reply." And whether it is keeping up at work or not losing track of friends, we cannot simply stop reading e-mail.

"We all get too much mail," Mr Smith explains, "and we all feel a certain desire - almost a moral responsibility - to respond. It's a real burden." As e-mail volumes increase, he predicts, we are going to be in real trouble.

"We're close to carrying capacity - we're close to the limit of human attention to messaging content. Simply because people do need to sleep and eat and they have some other work to do! I think we're buffeting up against the maximum number of user minutes per day available for managing this content.

"No one is giving me more heartbeats per day or more minutes. There is no Moore's Law for humans. I am not becoming twice as intelligent and half as cheap. If anything, the cost is going up and I'm slowing down.

"Given the real limits of human cognition, the machines - who have, after all, gotten us into this mess - are going to have to get us out of it."

He says e-mail software just does not give people enough help. He calls current software socially inept: "It simply has no conception of human relationships." His team is working on ways of making software "socially savvy" so that it can take more of the load.

Today, an e-mail inbox reflects what he calls "the ADD sort order" - assuming that just because something is new, it must be interesting.

"We found that 50 per cent of user minutes are focused at the top of the inbox. That's a sacred space, that's like my living room. You have to be invited into my living room and you should have to be invited into my inbox."

He wants to reclaim that space for the most relevant unread messages: in the real world, he says, "some people matter more than others" and software should take that into account.

"If you come to my home and knock on my door, I have a dog- my dog will bark. If you come back frequently, eventually the dog notices that you are a friend of the family - it does not bark, it wags its tail. Why is it that Outlook and other e-mail clients cannot be as smart as my dog?"

Rather than using rules and filters, he wants the system to work out who matters most to an individual. The first software his team has produced - the Social Network and Relationship Finder (Snarf) - looks at e-mail to calculate metadata that he calls "social accounting metrics".

At this stage, Snarf only looks at four things: "How many times have I sent this person mail before? And how many of those were replies? And how many times has this person sent me mail, and how many of those times were replies?" That is enough to make those people who a user is in conversation with - colleagues, friends and family - jump to the top of the list. Picking out the important messages helps when you're in a hurry: "Our canonical scenario is when you have been away from your e-mail for three hours and you have 11 minutes to eat lunch, review e-mail, and get to your next meeting. What should you read?"

The system can also be set in reverse to spot messages from new correspondents who might otherwise be drowned out.

He is searching for software that helps with today's shortage of time and attention: "If we can be more efficient with human attention, I think we can manage greater volumes.

"The same number of messages would be reviewed per day - they would just be the better messages."

Measures to manage inbox overload

Basic measures:

•Learn how filters work and use them to filter low-priority mail into mailboxes that can be checked periodically, rather than crowding your inbox.

•Filter out CC-ed messages or e-mails from sources that are high-volume but not vital.

•Turn off pop-up alerts.

For severe e-mail overload, Stever Robbins, business coach and columnist for Harvard Business School's Working Knowledge magazine, suggests radical measures:

•Train people to send relevant e-mails by making responses brief or, Robbins suggests, by replying with one word: "relevant?".

•Charge people to send you e-mails. Robbins says this works for a chief executive who deducts $5 (€4) from the budget of her staff for each one they send her.

•Delay responses to non-urgent e-mails, or don't answer e-mails at all.

Employ good e-mail practices yourself:

•Don't forward, CC or BCC messages to people who don't need them.

•If the topic has changed over the course of several messages, change the subject line to reflect more accurately the new content.

•Be aware of "threading": don't cover too many issues in one e-mail, but don't break them down into too many separate messages.

•Write detailed subject lines and be clear about action points.

•When sending an e-mail to multiple recipients, include a few words for each person if you require different responses or actions.