we got that message from MEG 7.6.3, mention below the error
Diagnostic-Code: smtp; 550 Please turn on SMTP Authentication in your mail client. ironmail.psopk.com|[18.104.22.168]:28181 is not permitted to relay through this server|without authentication.
kindly help me out in this case.
This indicates that the remote server requires authentication in order to allow you to send mail. The MEG is currently unable to do SMTP Authentication. If this is a feature that you require, please submit a PER (https://kc.mcafee.com/corporate/index?page=content&id=KB60021). If this is an external domain to whom you are intending to send mail, please contact their mail admins to get allowed to send them mail.