As 2011 draws to a close, Microsoft are rolling out their latest upgrade to their web based email client Windows Live Hotmail. While everyone’s email mix will be different, Hotmail is the world’s largest webmail service – serving over 360 million unique users a month – and should not be ignored. Outlined below are the changes Microsoft are making to the service:

• One-click Unsubscribe
  While this feature is available to Hotmail users already, how the unsubs will be handled is changing entirely. The one-click unsubscribe offers the user an unsubscribe link in Hotmail’s own interface and once these changes are made any emails which aren’t configured to work with the feature could result in future emails from the sender permanently being delivered to spam folders.
• Schedule Cleanup
  This feature offers Hotmail users the option for all emails or emails from one particular sender to be deleted or moved to a separate folder after a period of time. Depending on response times, this feature could lead to users never even seeing your email.
• Flagged Emails
  In a similar way to GMail’s priority inbox, Hotmail will begin keeping emails flagged as important at the top of the inbox. While this feature is unlikely to have much of an effect, marketers could see their emails pushed further down Hotmail’s inbox.
• Custom Categories
  By creating their own categories, users will be able to direct emails away from their inbox. For example, all retail emails could be delivered into a separate folder which may result in your email not being seen, let alone read.
• Folders
  Working in a similar way to custom categories, this feature will allow users to use Hotmail’s “sweep” to move certain emails from the inbox to separate folders. While both folders and custom categories are unlikely to have much of an impact, they do offer the user quick and easy ways to banish certain types of email from their inbox.

Guarding against the above changes will help to ensure your emails keep hitting the inbox, for a more detailed look into the changes, check out Tom Sather of Return Path’s post on the subject.