(Visual Basic 6.0) Send Encrypted Email with a Selected Algorithm (AES, 3DES, etc.)

Sends an encrypted email using the recipient's digital certificate from a .cer file, and chooses 3DES for the encryption algorithm. (It is also possible to send AES encrypted email w/ 128-bit, 192-bit, or 256-bit encryption simply by setting the Pkcs7CryptAlg and Pkcs7KeyLength properties.)

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

' This example requires the Chilkat API to have been previously unlocked.
' See Global Unlock Sample for sample code.

' The mailman object is used for sending and receiving email.
Dim mailman As New ChilkatMailMan

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

' Load the .cer file into a certificate object.
' When sending S/MIME encrypted email, it is the recipient's
' certificate that is used for encryption.  Only the public key
' is needed to encrypt.  The recipient is the only
' one possessing the private key, and therefore is the only
' one able to decrypt.
Dim cert As New ChilkatCert
Dim success As Long
success = cert.LoadFromFile("cknotes.cer")
If (success <> 1) Then
    Debug.Print cert.LastErrorText
    Exit Sub
End If

' Create a new email object
Dim email As New ChilkatEmail

email.Subject = "This email is encrypted"
email.Body = "This is a digitally encrypted mail"
email.From = "Chilkat Support <support@chilkatsoft.com>"
success = email.AddTo("Chilkat Blog","admin@cknotes.com")

' Indicate that the email is to be sent encrypted.
email.SendEncrypted = 1

' Specify the certificate to be used for encryption.
success = email.SetEncryptCert(cert)

' If desired, specify the encryption algorithm to be used.
' The Pkcs7CryptAlg property can be set to "aes", "des", "3des", or "rc2"
email.Pkcs7CryptAlg = "3des"

' If desired, set the key length (in bits) for the encryption algorithm:
' The possible values allowed depend on the Pkcs7CryptAlg property. 
' For "aes", the key length may be 128, 192, or 256. 
' For "3des" the key length must be 192. 
' For "des" the key length must be 40. 
' For "rc2" the key length can be 40, 56, 64, or 128.
email.Pkcs7KeyLength = 192

success = mailman.SendEmail(email)
If (success <> 1) Then
    Debug.Print mailman.LastErrorText
Else
    Debug.Print "Mail Sent!"
End If