Creating a Microsoft account gives you free access to Office for the web, Skype, OneDrive, Xbox and more, and will also give you an Outlook.com account. Read more about the benefits of a Microsoft account.
Limitations of creating an Outlook.com account using a third-party email address
You can create an Outlook.com or Microsoft account with a new email address or use an existing email address from a third-party email account, such as Gmail or Yahoo, but there are certain limitations when using a third-party email address as the primary alias for your Microsoft account.
When creating an Outlook.com account using a third-party email address, the email address must be a valid address to which you have access.
You can sign in to your Outlook.com mail and calendar with your third-party email address, but to access email from your third-party account, you must set it up as a connected account. See "Connected accounts" below.
Syncing is a one-way connection that goes from your third-party account to your Outlook.com account. Changes made in your third-party account will be reflected in Outlook.com, but changes made directly in Outlook.com won't appear in your third-party account.
If you send, reply to, forward, or delete email from your third-party account using Outlook.com, or make changes to your calendar or contacts there, the changes will appear only in Outlook.com.
After you've created your Outlook.com account, you'll want to connect your third-party account to it. By connecting your third-party account, you'll be able to use Outlook.com to send email from your third-party email address. You'll also be able to sync information from your third-party account to your Outlook.com account.
To add your third-party account as a connected account, see Add your other email accounts to Outlook.com. When adding your third-party account as a connected account in Outlook.com, you must use IMAP.
Note: Syncing between your third-party account and Outlook.com is only available for email (not calendar or contacts) and is one-way only. If you delete, move, or read an email from a connected account in Outlook.com, you won't see those changes when you go to your connected account.