The Connected accounts feature basically works as an email client, which connects to and fetches messages from Gmail, Yahoo or any other IMAP/POP account. While Connected accounts have certainly never been the most popular feature, they were useful for scenarios where you wanted to keep messages from all your email accounts across different providers in the same mailbox.
Now, Microsoft is deprecating support for the feature and will soon remove it from the service. No announcements or any other type of communication has been published on this yet, but those should be coming in the next few days/weeks. In the meantime, the official documentation has been updated with the following warning:
Important: Microsoft will be removing the ability to add new accounts to Outlook on the web using the Connected accounts feature in September 2018.
- You won’t be able to connect new accounts after September 15, 2018.
- Accounts that were connected before September 15th will continue to sync as usual until October 30, 2018.
- On October 30th, all connected accounts will stop syncing email.
- On November 15th, the Connected accounts option (Settings > Mail > Accounts) will be removed from Outlook on the web .
- Email that has already synced will continue to appear in your inbox unless you remove it manually.
In addition, the following alternatives have been suggested for people who want to keep receiving all their messages in the same account.
Notes: To continue seeing email from other accounts:
- Forward email from those accounts to Outlook on the web. For more information, see Turn on or off automatic forwarding in Outlook.com, Automatically forward Gmail messages to another account, and Automatic email forwarding in Yahoo Mail.
- Connect your other account to Outlook for Windows or Outlook for Mac (see Add an email account to Outlook).
- Connect your other account to Mail in Windows 10 (see https://support.microsoft.com/en-us/help/17198/windows-10-set-up-email).
- Download Outlook for iOS or Outlook for Android, which lets you sync your email, calendar, and contacts with other email accounts, easily switch between accounts, and offers a combined inbox, search, and an integrated calendar experience. For more information about how to set up Outlook mobile on your phone, see Outlook for iOS and Android Help Center.
As evident from the above text, the timeframe of this deprecation is rather short, so I decided to do my part and spread some awareness as well. Note that this deprecation only affects Office 365, for the time being Connected accounts in Outlook.com are safe.