Mail app unable to connect with Outlook.com account

Since about 9 hours ago, the native Mail app in my iPhone 5S (running iOS 12.5.4) is not able to connect to my Outlook.com email account using Exchange ActiveSync (which it successfully could earlier multiple times and this change happened all of a sudden without any configuration changes on my part).

Things which I have tried but failed to solve the problem:

1. Restarting the phone
2. Resetting the network settings (which included a restart)
3. Using a different Internet connection
4. Using a different set of DNS servers with my current Internet connection
5. Connecting with both SSL enabled and disabled in the advanced account settings of the Outlook.com account

I am also not able to add a fresh Outlook.com account as well, so I don't think the problem is with my existing account(such that I should try removing it and adding it back again). In both cases, I get the error message "Unable to verify account information". My Outlook.com account credentials are valid and work properly when logging in using the browser. Also, in my native Mail app, I have other email accounts too, such as Gmail, Yahoo, etc. They all work properly.