To show just what that means, Microsoft released a fun infographic. If all that data was all in the MP3 music file format, it'd take you 300,000 years to bop your way through what would be quite a hefty playlist. If it remained in email form, it would take you 120 million years to get through it all -- at a rate of a mere 50 a day, it has to be said.
The IT giant's Outlook group program manager Dick Craddock wrote in a blog that the new email system has some 300 million accounts moved over from Hotmail and 100 million fresh ones, making this a 400 million address system now.
[ Perhaps Microsoft can now shifts its focus to other challenges. Read 10 Ways Microsoft Could Improve Surface Tablets. ]
That's a nice stat, though Microsoft's main rival Google is still ahead, though not by much, with 425 million accounts as of June. Microsoft says one of the program goals with Outlook is get to a billion active users.
In addition to switching customers to new email handles and domains, Microsoft added new features, including a new calendar, Android app (since 125 of the 400 million access their Outlook email, calendar and contacts on a mobile device using Exchange ActiveSync) and support for two-factor authentication. Next up: SMTP send, "so it's easier to send mail from different email addresses," and "deeper integration" with the cloud data facility SkyDrive, Craddock said.
"Hotmail was still one of the most widely used services, with over 300 million active accounts," he wrote. "This made the magnitude of the process incredible, maybe even unprecedented. This meant communicating with hundreds of millions of people, upgrading all their mailboxes and 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."
So, farewell Hotmail, which almost certainly had users active on it since its 1996 debut.