Unable to create a new account in Mailspring

I have already successfully created two accounts in the free version of Mailspring, a gmail account and my private one related to my own domain and they are working fine… I’m trying to add my Live.co.uk account but keep being told “Authentication Error - Check your username and password. (SMTP)” I know that my user name and password are correct and I’ve tried several SMTP port settings, (smtp-mail.outlook.com) (25, 465,587 ) with different security, but try as I might I cannot set up the account. Any help with this really annoying problem would be most appreciated… Kind Regards