SMTP Unrecognized authentication type

Oct 7, 2015 at 7:04 PM
I have a web application which sends emails through a server in my company's network.
I use .NET SmtpClient class to send emails and it works fine.
But since I want to track bounced back emails, i started using your library.
However, I'm having problem with authenticating to my email server using ActiveUp.Net.Mail.SmtpClient class.
The exception is: 504 5.7.4 Unrecognized authentication type.
It works fine is I use .NET SmtpClient class.

This is the source code with .NET SmtpClient:
var objsmtp = new SmtpClient(objmail.SMTPNameorIP, 25);
objsmtp.Credentials = new NetworkCredential(objmail.SMTPUserName, objmail.SMTPPassword);

Source code with ActiveUp.Net.Mail.SmtpClient class:
ActiveUp.Net.Mail.SmtpClient clt = new ActiveUp.Net.Mail.SmtpClient();
clt.Connect("server ip address", 25);
clt.Helo("server ip address");
clt.Authenticate("username", "password", SaslMechanism.Login);

Thank you and best regards.
Oct 8, 2015 at 10:25 PM
I would highly recommend using MailKit instead.

That said, the problem is probably that the server does not support the LOGIN SASL mechanism.

Also, the HELO command should be sent using your client's IP address or hostname, not the server's.

With MailKit, you don't have to worry about either of these things, it just does the Right Thing (tm) for you.