CDO 在 VBScript 中工作，但在 C# 中不工作

Question

我有一个 VBScript 文件来发送电子邮件它工作正常，但是当我创建一个具有相同 CDO 设置的 C# 程序 (.Net 4.5) 时

传输无法连接到服务器。

请检查我的 C# 有什么问题。

VBScript：

Dim objMessage
Set objMessage = CreateObject("CDO.Message") 

objMessage.Subject = Subj 
objMessage.From = Sender
objMessage.To = Receivers

objMessage.TextBody = Body 

objMessage.Configuration.Fields.Item("http://schemas.microsoft.com/cdo/configuration/sendusing") = 2

objMessage.Configuration.Fields.Item("http://schemas.microsoft.com/cdo/configuration/smtpserver") = ServerName

objMessage.Configuration.Fields.Item ("http://schemas.microsoft.com/cdo/configuration/smtpserverport") = 25 
objMessage.Configuration.Fields.Item ("http://schemas.microsoft.com/cdo/configuration/smtpconnectiontimeout") = 60
objMessage.Configuration.Fields.Item ("http://schemas.microsoft.com/cdo/configuration/smtpauthenticate") = 2

objMessage.Configuration.Fields.Item ("http://schemas.microsoft.com/cdo/configuration/sendusername") = ""
objMessage.Configuration.Fields.Item ("http://schemas.microsoft.com/cdo/configuration/sendpassword") = ""
objMessage.Configuration.Fields.Item ("http://schemas.microsoft.com/cdo/configuration/smtpusessl") = False

objMessage.Configuration.Fields.Update

objMessage.Send

C#：

using System.Net.Mail;
...
CDO.Message  objMessage   = new CDO.Message();

objMessage.Subject = Subj;
objMessage.From = Sender;

objMessage.To = Receivers;
objMessage.TextBody = Body;

ADODB.Field FieldSMTPSendUsing = objMessage.Configuration.Fields["http://schemas.microsoft.com/cdo/configuration/sendusing"];
FieldSMTPSendUsing.Value = 2;

ADODB.Field FieldSMTPServer = objMessage.Configuration.Fields["http://schemas.microsoft.com/cdo/configuration/smtpserver"];
FieldSMTPServer.Value = ServerName; 

ADODB.Field FieldSMTPServerPort = objMessage.Configuration.Fields["http://schemas.microsoft.com/cdo/configuration/smtpserverport"];
FieldSMTPServerPort.Value = 25;

ADODB.Field FieldSMTPconnectiontimeout = objMessage.Configuration.Fields["http://schemas.microsoft.com/cdo/configuration/smtpconnectiontimeout"];
FieldSMTPconnectiontimeout.Value =  60 ;

ADODB.Field FieldSMTPauthenticate = objMessage.Configuration.Fields["http://schemas.microsoft.com/cdo/configuration/smtpauthenticate"];
FieldSMTPauthenticate.Value = 2;

ADODB.Field FieldSMTPsendusername = objMessage.Configuration.Fields["http://schemas.microsoft.com/cdo/configuration/sendusername"];
FieldSMTPsendusername.Value = "";

ADODB.Field FieldSMTPsendpassword = objMessage.Configuration.Fields["http://schemas.microsoft.com/cdo/configuration/sendpassword"];
FieldSMTPsendpassword.Value = "";

ADODB.Field FieldSMTPusessl = objMessage.Configuration.Fields["http://schemas.microsoft.com/cdo/configuration/smtpusessl"];
FieldSMTPusessl.Value = false;

objMessage.Configuration.Fields.Update();

objMessage.Send();

Answer 1

不要在 C# 中使用 CDO。使用MailMessage 类编写消息，使用SmtpClient 类发送消息。

MailMessage message = new MailMessage(Sender, Receivers, Subj, Body);

SmtpClient client = new SmtpClient(ServerName);

try {
  client.Send(message);
} catch (Exception ex) {
  Console.WriteLine("Cannot send message.");
}