IF OPENING your groaning email inbox on returning from vacation fills you with dread, help is at hand. Free software developed by Microsoft Research in Redmond, Washington, will sort through your inbox and prioritise messages from people it deems are most important to you.

The program groups emails by sender, and then prioritises senders according to the number of times that you have communicated with them recently and the frequency with which you reply to them. So you should be able to home in on emails that are likely to be especially urgent or interesting.

Called the Social Network and …