Как решить ошибку LNK2019
Я отправляю простое письмо на C ++. Я скачал образец программы на C ++ по ссылке ниже.http://cboard.cprogramming.com/cplusplus-programming/125655-sending-simple-email-cplusplus.html Программа-пример, кажется, натолкнулась на следующую ошибку при компиляции. Пожалуйста, помогите мне с решением.
Error 8 error LNK2019: unresolved external symbol _send_mail referenced in function _wmain
Error 9 error LNK2019: unresolved external symbol __imp__recv@16 referenced in function "int __cdecl connect_to_server(char const *)" (?connect_to_server@@YAHPBD@Z)
Error 10 error LNK2019: unresolved external symbol __imp__connect@12 referenced in function "int __cdecl connect_to_server(char const *)" (?connect_to_server@@YAHPBD@Z)
Error 11 error LNK2019: unresolved external symbol __imp__htons@4 referenced in function "int __cdecl connect_to_server(char const *)" (?connect_to_server@@YAHPBD@Z)
Error 12 error LNK2019: unresolved external symbol __imp__socket@12 referenced in function "int __cdecl connect_to_server(char const *)" (?connect_to_server@@YAHPBD@Z)
Error 13 error LNK2019: unresolved external symbol __imp__getprotobyname@4 referenced in function "int __cdecl connect_to_server(char const *)" (?connect_to_server@@YAHPBD@Z)
Error 14 error LNK2019: unresolved external symbol __imp__gethostbyname@4 referenced in function "int __cdecl connect_to_server(char const *)" (?connect_to_server@@YAHPBD@Z)