I receive the following error message:
Technical details
InvalidRecipientsException: Invalid recipients were provided for the message: ‘25c2’ (550-Requested action not taken: mailbox unavailable 550 invalid DNS MX or A/AAAA resource record ). → Unexpected SMTP server response. Expected: 250, actual: 550, whole response: 550-Requested action not taken: mailbox unavailable 550 invalid DNS MX or A/AAAA resource record Failure code: 476e
Thank you so much for your help in advance!
Best
Frederik