C # send an email with an attachment

I found a lot of email sending code on the Internet and found a connection problem. For example, TCP = new tcpclient (server, Port); server = smtp.126.com, Port = 25, cannot connect, in the following simple example, If you disable the firewall and McAfee antivirus software, you can send emails with attachments.

Using system;
Using system. Web. mail;

Namespace egxsun
{
///

/// Summary of systemmail.

///

Public class systemmail

{

Private string _ adminemail;

Private string _ smtpserver = "localhost ";

Private string _ password;

Private string _ username;

 

Public systemmail ()

{

}

 

Public String adminemail

{

Get {return _ adminemail ;}

Set {_ adminemail = value ;}

}

 

Public String smtpserver

{

Get {return _ smtpserver ;}

Set {_ smtpserver = value ;}

}

 

Public String Password

{

Get {return _ password ;}

Set {_ password = value ;}

}

 

Public String Username

{

Get {return _ username ;}

Set {_ username = value ;}

}

 

Public bool send (string to, string from, string subject, string message)

{

Try

{

Mailmessage em = new mailmessage ();

Em. To =;

Em. From = from;

Em. Subject = subject;

Em. Body = message;

Em. attachments. Add (New mailattachment ("FILENAME "));

// Found out how to send authenticated email via system. Web. Mail at http://SystemWebMail.com (fact 3.8)

If (this. Username! = NULL & this. Password! = NULL)

{

Em. Fields. Add ("http://schemas.microsoft.com/cdo/configuration/smtpauthenticate", "1"); // Basic Authentication

Em. Fields. Add ("http://schemas.microsoft.com/cdo/configuration/sendusername", this. username); // set your username here

Em. Fields. Add ("http://schemas.microsoft.com/cdo/configuration/sendpassword", this. Password); // set your password here

}

 

Smtpmail. smtpserver = This. smtpserver;
Smtpmail. Send (EM );

Return true;

}

Catch

{

Return false;

}

}
Public bool send (string to, string from, string subject, string body, string filename)

{

Try

{

Mailmessage em = new mailmessage ();

Em. To =;

Em. From = from;

Em. Subject = subject;

Em. Body = body;

Em. attachments. Add (New mailattachment (filename ));

// Found out how to send authenticated email via system. Web. Mail at http://SystemWebMail.com (fact 3.8)

If (this. Username! = NULL & this. Password! = NULL)

{

Em. Fields. Add ("http://schemas.microsoft.com/cdo/configuration/smtpauthenticate", "1"); // Basic Authentication

Em. Fields. Add ("http://schemas.microsoft.com/cdo/configuration/sendusername", this. username); // set your username here

Em. Fields. Add ("http://schemas.microsoft.com/cdo/configuration/sendpassword", this. Password); // set your password here

}

 

Smtpmail. smtpserver = This. smtpserver;

Smtpmail. Send (EM );

Return true;

}
Catch // (exception ex)
{
// String Ss = ex. tostring ();
Return false;

}

}
 

}
}
 

Usage:

Systemmail Sm = new systemmail ();
SM. smtpserver = "smtp.126.com ";
SM. Username = "******";
SM. Password = "******";
If (Sm. Send ("sunssss@126.com", "egxsun@126.com", "title", "body", @ "C:/deltable.rar "))
{
MessageBox. Show ("sent successfully! ");
}
Else
{
MessageBox. Show ("failed to send! ");
}