Send S/MIME Signed Email

Send digitally signed email using the digital certificate of the recipient. To successfully sign, the sender's certificate must be pre-installed with private key. Typically, this is done via a .pfx file, or through Internet Explorer. If your code is going to run within ASP, ASP.NET, or a Windows Service, you will need to follow the instructions here (http://blog.chilkatsoft.com/?p=149) to import your certificate w/ private key such that it is accessible by the calling process.

Download Chilkat .NET for 2.0 / 3.5 Framework

Download Chilkat .NET for 1.0 / 1.1 Framework

'  The mailman object is used for sending and receiving email.
Dim mailman As New Chilkat.MailMan()

'  Any string argument automatically begins the 30-day trial.
Dim success As Boolean
success = mailman.UnlockComponent("30-day trial")
If (success <> true) Then
    MsgBox("Component unlock failed")
    Exit Sub
End If


'  Set the SMTP server.
mailman.SmtpHost = "smtp.chilkatsoft.com"

mailman.SmtpUsername = "myLogin"
mailman.SmtpPassword = "myPassword"

'  Create a new email object
Dim email As New Chilkat.Email()

email.Subject = "This email is signed"
email.Body = "This is a digitally signed mail"
email.From = "Chilkat Support <admin@chilkatsoft.com>"
email.AddTo("Test","test@testemail.net")

'  In this example, we've already installed the certificate for "admin@chilkatsoft.com"
'  (with private key) in the current user's personal certificate store.
'  If the email.SendSigned property is set, Chilkat will
'  automatically search for and use the first non-expired certificate
'  matching the sender's email address.  Chilkat searches
'  the Current User's Personal certificate store, as well
'  as the Local Machine's Personal certificate store.
'  Run certmgr.msc to view the certs in the Current User's
'  certificate store.
email.SendSigned = true

success = mailman.SendEmail(email)
If (success <> true) Then
    MsgBox(mailman.LastErrorText)
Else
    MsgBox(mailman.LastErrorText)
    MsgBox("Mail Sent!")
End If