Hotmail helps users register and validate their e-mail address by connecting to their other e-mail service and importing existing email. The POP3 protocol is used to deliver non-Hotmail e-mail to a Hotmail inbox. On the flipside, Hotmail's "Send As" feature lets users appear to send e-mail from their non-Hotmail account. In other words, Microsoft is porting basic functions from e-mail clients such as Microsoft Outlook to the Web.
Microsoft is hoping EASI ID will mean more people consolidating their multiple e-mail addresses into Hotmail. Even if they don't switch, the implementation means users can try out what Hotmail has to offer without much effort (over 30 million people currently use Windows Live ID with a separate e-mail address). As you can see in the screenshot above, Microsoft's example shows a Hotmail inbox that is integrated with a Gmail account.
"Implementing this was fairly straightforward given the architecture of Hotmail, our POP aggregation support, and the 'Send As' feature that lets you send mail from any validated email address," Dick Craddock, group program manager for Windows Live Hotmail, said in a statement. "We just needed to tweak the way we store and look up email addresses, build the first-run experience, and we had it."