<PackageReference Include="NETStandard.Library" Version="2.0.3" />

System.Net.Mail.SmtpClient

public class SmtpClient : IDisposable
namespace System.Net.Mail { public class SmtpClient : IDisposable { public X509CertificateCollection ClientCertificates { get; } public ICredentialsByHost Credentials { get; set; } public SmtpDeliveryFormat DeliveryFormat { get; set; } public SmtpDeliveryMethod DeliveryMethod { get; set; } public bool EnableSsl { get; set; } public string Host { get; set; } public string PickupDirectoryLocation { get; set; } public int Port { get; set; } public ServicePoint ServicePoint { get; } public string TargetName { get; set; } public int Timeout { get; set; } public bool UseDefaultCredentials { get; set; } public event SendCompletedEventHandler SendCompleted; public SmtpClient(); public SmtpClient(string host); public SmtpClient(string host, int port); public void Dispose(); protected virtual void Dispose(bool disposing); protected void OnSendCompleted(AsyncCompletedEventArgs e); public void Send(MailMessage message); public void Send(string from, string recipients, string subject, string body); public void SendAsync(MailMessage message, object userToken); public void SendAsync(string from, string recipients, string subject, string body, object userToken); public void SendAsyncCancel(); public Task SendMailAsync(MailMessage message); public Task SendMailAsync(string from, string recipients, string subject, string body); } }