Users of Outlook (or Hotmail) email accounts are having some issues with third-party email apps, preventing them from receiving and sending emails using those apps. The issue was reported to Microsoft on September 24th, and the company says it's investigating the problem. The company has even provided a workaround, which involves setting up accounts as Exchange accounts, but that won't work for everyone.
Multiple reports have also appeared on the community forums for eM Client, a third-party email app for Windows, and that's where we can find more answers. Here's what's happening: When setting up an email account with a third-party app, you'll often just be asked for your account credentials. Using a standard called OAuth, email clients can then communicate with the email provider (Outlook, in this case) and obtain the necessary information to receive your email data from the server. As reported by some users on Microsoft's forums and indicated by user Gary on the eM Client community, the OAuth certificate provided by Microsoft is the issue here, as it's not allowing Outlook accounts to be connected to the email server through these apps.
One solution that Microsoft initially provided was mentioned above - adding your email account as an Exchange account, rather than an IMAP account, which is the more "standard" protocol for emails. However, free Hotmail/Outlook accounts can't connect to Exchange servers, so this will only work for business accounts.
However, eM Client user Gary has provided another solution for free/personal Outlook accounts. Since OAuth won't allow email clients to obtain data from Outlook servers to receive email, all the user needs to do is set up the email servers manually. The steps to do this will naturally vary depending on your email client, but you'll need to set up the account to use the following servers:
- Incoming email / IMAP: imap-mail.outlook.com
- Outgoing email / SMTP: smtp-mail.outlook.com
This, in addition to your Outlook credentials, will allow you to keep receiving and sending email using third-party apps, at least until Microsoft fixes its ongoing issues with OAuth. If that doesn't work in your email client, Microsoft has a more detailed list of the settings you'll need to use to set up third-party email apps manually. It's also worth pointing out that, for unknown reasons, the Gmail app for Android still seems to connect to Outlook accounts just fine, according to Neowin, and we were also able to connect with no issues using Mozilla Thunderbird. Thunderbird doesn't use OAuth by default, which is probably why it works.
As of today, the company has said that it's still investigating the full extent of the email issues, and recognized that switching protocols (as it had suggested) isn't a viable option for everyone. Hopefully, a fix will come sooner rather than later and these steps will become unnecessary.