<p>Microsoft's decision to get rid of Hotmail and replace it with Outlook.com appears to have paid off. With all Hotmail users now migrated to Outlook.com, Microsoft says it now has more than 400 million active accounts on the well-designed email service.</p><p>Outlook.com launched to positive reviews back in July 2012. A few months ago, Outlook.com exited preview with 60 million registered users. But the brunt of the work wasn't done at that point because it still needed to move its many Hotmail users over to Outlook.com.</p><p>Microsoft said it migrated 150 petabytes of email in six weeks. The company writes in a blog post:</p><p>When Outlook.com came out of preview in February, it already had more than 60 million active accounts. However, Hotmail was still one of the most widely used services, with over 300 million active accounts. This made the magnitude of the process incredible, maybe even unprecedented. This meant communicating with hundreds of millions of people, upgrading all their mailboxesequaling more than 150 million gigabytes of dataand making sure that every person's mail, calendar, contacts, folders, and personal preferences were preserved in the upgrade. Of course, this had to be done with a live site experience that was handling billions of transactions a day. With your help, we were able to do all of that in just about 6 weeks. We've spent the last few weeks ensuring that everything was completed in line with our high quality expectations.</p><p><a href="http://venturebeat.com/2013/05/02/microsoft-outlook-com-400-million-accounts/">Keep reading...</a></p><p>Read also:</p><p><a href="http://gigaom.com/2013/05/02/microsoft-weve-migrated-400m-hotmail-users-to-outlook-com/">Microsoft: We've migrated 300M Hotmail users to Outlook.com</a> (GigaOM)</p><p><a href="http://www.ghacks.net/2013/05/02/goodbye-hotmail-microsoft-completes-hotmail-to-outlook-migration/">Goodbye Hotmail! Microsoft completes Hotmail to Outlook migration.</a> (Ghacks Technology News)</p><p><a href="http://www.engadget.com/2013/05/02/microsoft-finishes-migrating-hotmail-users-to-outlook-com/">Microsoft finishes migrating Hotmail users to Outlook.com, adds direct ...</a> (Engadget)</p><p>Explore: <a href="http://news.google.com/news/more?ncl=dl2jLL2oFJPASMMaQlZO_B5ZtKmGM&ned=us">29 additional articles.</a></p>