<p>SAN FRANCISCO Microsoft is so confident it has the Internet's best e-mail service that it is about to spend at least $30 million to send its message across the United States.</p><p>The barrage began Tuesday when Microsoft's twist on e-mail, Outlook.com, escalated an assault on rival services from Google Inc., Yahoo Inc., AOL Inc., and a long list of Internet service providers.</p><p>As part of the process, all users of Microsoft's Hotmail and other e-mail services operating under different domains such as MSN.com will be automatically converted to Outlook.com by the summer, if they don't voluntarily switch before then. All the old messages, contacts, and settings in the old inboxes will be exported to Outlook.com. Users will also be able to keep their old addresses.</p><p>E-mail remains a key battleground, even at a time when more people are texting each other on phones.</p><p><a href="http://bostonglobe.com/business/2013/02/20/microsoft-outlook-takes-aim-google-gmail/0dgl8EZXYSKZ0c2vUuGf3N/story.html">Keep reading...</a></p><p>Read also:</p><p><a href="http://www.wired.com/gadgetlab/2013/02/microsoft-outlook-webmail/">60 Million Microsoft Outlook.com Users Isn't All That</a> (Wired)</p><p><a href="http://www.usatoday.com/story/tech/columnist/baig/2013/02/18/outlookcom-email-loses-preview-tag/1929301/">Microsoft Outlook.com email: No longer in preview</a> (USA TODAY)</p><p><a href="http://www.pcmag.com/article2/0,2817,2415566,00.asp">Microsoft's Outlook.com Gains 60M Users, Exits Preview</a> (PC Magazine)</p><p>Explore: <a href="http://news.google.com/news/more?ncl=dzZs2R2YI4et8vMQDodfh-kfAg-aM&ned=us">619 additional articles.</a></p>