Not quite--this predates .net. They acquired Hotmail in 1997, while it was running on Solaris mail servers and Apache on FreeBSD for the web frontend. In a highly publicized move, Microsoft ventured to port it to Exchange and IIS on Windows NT. This went on for years on end, with MS claiming to have finished the transition several times, while getting egg on their face. Eventually, they got it running on Windows 2000 and a combination of their flagship products and Windows Services for Unix (the WSL of those times).
It has since been rebranded as MSN Hotmail, Windows Live Hotmail, Hotmail, and Outlook, likely with some 365 thrown in.
Meanwhile, they have mismanaged their once great mail user agent Outlook Express, as well as their quite useful personal information manager Microsoft Outlook, to the point where their newest offering is absolutely unusable.
It has since been rebranded as MSN Hotmail, Windows Live Hotmail, Hotmail, and Outlook, likely with some 365 thrown in.
Meanwhile, they have mismanaged their once great mail user agent Outlook Express, as well as their quite useful personal information manager Microsoft Outlook, to the point where their newest offering is absolutely unusable.