Error getting when hosting windows service

Hi..
I wrote a windows service...in that on start method I wrote following code.

          Member oMember = new Member();
          
            oMember.SendEmail("myname@gmail.com","password");


I have taken my project .dll into windowservice project thorugh add reference.
In my .dll I have class "Member". And I have wrote code to send Email.
Here I got build succeded. But I am trying register this service with my O.S i am getting error.
Pls suggest he How solve this.

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