Facing problem while sending email

System.Net.Mail.SmtpException: System.Net.Mail.SmtpException: The SMTP server requires a secure connection or the client was not authenticated. The server response was: 5.7.0 Authentication Required. Learn more at
at System.Net.Mail.MailCommand.CheckResponse(SmtpStatusCode statusCode, String response)
at System.Net.Mail.MailCommand.Send(SmtpConnection conn, Byte command, MailAddress from, Boolean allowUnicode)
at System.Net.Mail.SmtpTransport.SendMail(MailAddress sender, MailAddressCollection recipients, String deliveryNotify, Boolean allowUnicode, SmtpFailedRecipientException& exception)
at System.Net.Mail.SmtpClient.Send(MailMessage message)
at ManagerServer.HttpHandlers.Businesses.Business.SendEmail.Post()

Read the guide about troubleshooting email problems and post the information demanded here

Troubleshoot email issues | Manager

did not get solution

To get further help you need to post details of your Manager installation (version and edition), your operating system, your email service provider

There are guides for some email services too, so if you use one of them you should read those guides.

Post screen images of your email settings hiding and passwords