ko Đặt lại mật khẩu và gửi vào email đăng ký được là sao ạ

ko Đặt lại mật khẩu và gửi vào email đăng ký được là sao ạ

Server Error in ''/'' Application.
No connection could be made because the target machine actively refused it
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.Net.Sockets.SocketException: No connection could be made because the target machine actively refused it

Source Error:

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.
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huhu sao thế ạ?