SMTP Authentication / NTLM / SSL / STARTTLS

Download Chilkat Email ActiveX

This article discusses SMTP authentication issues with the Chilkat mail component.

    ' This example discusses SMTP authentication
    '
    ' If your SMTP server requires authentication, you will need
    ' to set the ChilkatMailMan2.SmtpUsername and SmtpPassword properties.
    ' NOTE: Some SMTP servers require authentication when your program
    ' connects from outside a firewall, but do not require authentication
    ' when connecting from within it's own network (i.e. on the same side
    ' of the firewall as the SMTP server).
    '
    ' The ChilkatMailMan2.SmtpAuthMethod can explicitly control the
    ' authentication method used by the Chilkat email component.
    ' By default, it is set to an empty string which indicates that
    ' the most secure authentication method supported by the SMTP server
    ' should be used.  This is typically NTLM or CRAM-MD5.
    ' For most cases, you should never need to set the SmtpAuthMethod property.
    '
        
    ' Create an instance of the mailman for the purpose of unlocking.
    Dim mailman As New ChilkatMailMan2
    mailman.UnlockComponent "Anything for 30-day trial"
    
    ' Create a new email object...
    Dim email As New ChilkatEmail2
    email.Subject = "This is a test"
    email.Body = "This is the mail body"
    email.AddTo "Chilkat Support", "support@chilkatsoft.com"
    email.From = "Chilkat Sales <sales@chilkatsoft.com>"
    
    ' We can send the email like this:
    mailman.SmtpHost = "smtp.comcast.net"
    ' If the SMTP server does not require authentication, these two
    ' lines can be omitted.
    mailman.SmtpUsername = "myLogin"
    mailman.SmtpPassword = "myPassword"
        
    ' If there is a problem with authentication, the "LOGIN" method is surely supported:
    mailman.SmtpAuthMethod = "LOGIN"
    
    ' However, if you use the "LOGIN" method of authentication, your SMTP username/password
    ' is sent over the Internet unprotected.  A good way of solving this is to
    ' use SMTP SSL:
    mailman.SmtpSsl = 1     ' Tell the mailman to connect via SSL
    mailman.SmtpPort = 465  ' Most SMTP servers listen at port 465 for SSL connections.
    ' Now you can use LOGIN authentication because everything is protected by the SSL connection.
    
    ' An alternative is to use STARTTLS.  This means that the SMTP server is initially
    ' connected on a normal, unsecure connect at the default SMTP port 25.
    mailman.SmtpSsl = 0
    mailman.SmtpPort = 25
    mailman.StartTLS = 1
    ' The StartTLS option causes the connection to be converted to an SSL/TLS connection
    ' such that the authentication and mail sending occurs over a secure channel.
    
    success = mailman.SendEmail(email)
    If (success = 0) Then
        MsgBox mailman.LastErrorText
    Else
        MsgBox "Mail Sent!"
    End If