The main problem is that, for the past three days, the Hotmail inbox has had some kind of problem despite the correct authentication. The connectivity is also correct, as shown by the message "A secure connection has been successfully established with outlook.office365.com:993." I tried cleaning the cache, but the problem continued. All the other accounts are working fine, as expected, including another Hotmail account. I've fixed the problem on another computer by cleaning the cache, and it's running OK now.