Can you help me?
I am having the same issue with an email account on my new windows 11 pc. I'm try to use an IMAP protocol mail.twc.com account. The old outlook app will not send or receive and I get no error messages. The new outlook receives emails OK but will not send. (BTW My old windows 10 pc with old outlook works fine with this email server.)
I get the following error on my new pc with new outlook trying to send email:
Technical details
SmtpSubmissionPermanent5XXException: Smtp submission failed. Server 'mail.twc.com' Port '587'. --> Unexpected SMTP server response. Expected: 235, actual: 535, whole response: 535 5.7.0 ...authentication rejected
Failure code: cf24