Error Sending Mail - The server response was:5.7.57 SMTP, Client was not authenticated to send anonymous mail

Question

while sending Email for ForgotPassword in my application i'm getting this Error.

The SMTP server requires a secure connection or the client was not authenticated. The server response was: 5.7.57 SMTP; 
Client was not authenticated to send anonymous mail during MAIL FROM [XXXXXXXXXX.xxxxxxxxx.prod.outlook.com]

i referred following Links and Solutions

5-7-57-smtp-client-was-not-authenticated-to-send

The-server-response-was-SMTP-Client-was-not-authen

5757-smtp-client-was-not-authenticated-to-send-anonymous-mail-during-mail-from

i tried changing the port, Added Domain along with Credentials, Changed client.UseDefaultCredentials to false and placed above credentials.

still getting this same error every time and no solutions helped.

please suggest if anyone have the solution.

Thank you.