In May 2015, Microsoft announced a major upgrade for Outlook.com, introducing a wide range of new features and improvements for users of its webmail service. Nine months later, the company announced in February of this year that the overhauled service had finally emerged from preview, and its general rollout would begin.
At the end of April, Microsoft said it had already upgraded almost half of its 400 million Outlook.com users to the new experience, and added that it expected to have the "majority upgraded by the end of summer".
Now, it"s issued a further update on its plans, saying that "everyone will be migrated over by the end of summer at the latest."
That"s an improvement on its earlier, somewhat more vague commitment to upgrading a "majority" of users by then, and indicates that by the end of September, the transition to its new Outlook.com experience - powered by Office 365 - will finally be complete.
By that time, almost a year and a half will have passed since Microsoft"s original announcement.
Source: @Outlook via MSPoweruser