Unable to send Mails from Zammad

Hello,

mailboxes were integrated via the Office 365 integration so that all emails sent to the IT hotline now land in the ticket system. However, when replying to the email through the ticket system, the following error appears: Delivery failed “Unable to send email to ‘dominik.wagenbrenner@troeger-gmbh.de’. Can’t use Channel :: Driver :: Smtp #<Net::SMTPAuthenticationError: Net::SMTPAuthenticationError>”

any ideas?

Hi @Leon. Please see here.