Not able to send email from desktop Outlook - failure code ad29

Hello there, I have an issue with sending emails from desktop Outlook app as shown below (failure code ad29). I already tried solution recommended here https://learn.microsoft.com/en-us/answers/questions/5986707/how-to-fix-the-problem?page=1&orderby=Helpful&comment=answer-12932633&translated=false#newest-answer-comment but is not helping in my case. I even tried to delete my mail account from otlook and add it again, no difference. Sending mail from webmail works, from outlook on mobile as well. What should I do next? Thank you

MessageDeliveryFailedException: Could not deliver the message [len=70, 
Failure code: ad29