System is unable to process your request. Please check: -Recipient Email Address -Your server status

Hello ALL,
i am facing a strange issue , while i am reset user password from user module record error popup occur with this state :

System is unable to process your request. Please check: -Recipient Email Address -Your server status”\

Thanks advance

and also i can sent test emil from email configuration .

but when request reset user password for any user from detIL view buttons list, show e the error as i mentioned above …
and in logs “SugarPHPMailer encountered an error: SMTP Error: Could not authenticate.”…