Earlier this year, news leaked that Microsoft was testing a new version of its Outlook email platform that introduced new, premium features for a $3.99 per month fee. While there is still no formal launch date for Outlook Premium, the company has now started an invite-only pilot program for the service.

Signing up for Outlook Premium will let you create five personalized email addresses with your own custom domain names, which is good news for those users who prefers something other than a @outlook.com, @live.com, or @hotmail.com address.

Sign-ups will also get better calendar, contact, and document sharing features, as well as an ad-free inbox. Additionally, you won’t be charged for the first 12 months of using Outlook Premium, and it’s free to Office 365 subscribers. The subscription only starts at the end of the first year, giving you plenty of time to decide if it’s worth the monthly fee.

It's Microsoft's partnership with GoDaddy that allows Outlook Premium users to customize their email address domains. After the year’s free trial has expired, however, these domains aren’t automatically renewed with Premium or Office 365 subscriptions; keeping them will require customers to visit GoDaddy.com, according to the FAQ.

While having no ads in Outlook Premium may sound appealing, Microsoft already offers an ad-free version of the email service for the lower price of $19.95 a year. It doesn’t come with any of the other features offered in the Premium package, though.

Microsoft hasn’t said anything else about the program, other than issuing the following statement:

Outlook.com Premium is currently a small pilot program. We’re always investigating new features based on the wants and needs of our customers, and we have nothing more to share at this time.