(PowerShell) 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 .NET Downloads Chilkat .NET Assemblies

Add-Type -Path "C:\chilkat\ChilkatDotNet47-9.5.0-x64\ChilkatDotNet47.dll"

# 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.
$mailman = New-Object Chilkat.MailMan

# 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.
$cert = New-Object Chilkat.Cert
$success = $cert.LoadFromFile("cknotes.cer")
if ($success -ne $true) {
    $($cert.LastErrorText)
    exit
}

# Create a new email object
$email = New-Object Chilkat.Email

$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 = $true

# 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 -ne $true) {
    $($mailman.LastErrorText)
}
else {
    $("Mail Sent!")
}