Today when I launched Microsoft Outlook, I was greeted by an error which said, “Your IMAP server wants to alert you to the following: Web login required. (Failure)”.
And I was prompted to input the password again which I was sure wasn’t wrong. Digging into Gmail Help, I found the root cause of the problem, “The frequency of mails being checked using IMAP protocol” which in case here was Outlook. Gmail Help Clearly explains :
Make sure your mail client isn’t set to check for new mail too often. If your mail client checks for new messages more than once every 10 minutes, your client might repeatedly request your username and password.
And the only way to get rid of this error was to perform captcha check to unlock account with your correct password.
If the issue persists:
I was able to resolve this issue by following the step above and the error was resolved for me. Remember this precaution is in place for security reasons, so no bots are able to access data like this.
Another solution to avoid falling into this kind of situation will be to reduce the polling frequency set for Outlook to check for new email. This way you will not be hitting the mail server all the time and Gmail will never ask you for password.