.NET Core C#

Load .eml and Decrypt (smime.p7m)

Loads an encrypted email from a .eml file and decrypts using certificate w/ private key found in a .p12 (or .pfx) file.

The Content-Type and Content-Disposition email headers of the email to be decrypted look similar to this:

Content-Type: application/x-pkcs7-mime; smime-type=enveloped-data;
	name="smime.p7m"
Content-Disposition: attachment; filename="smime.p7m"

.NET Core C#

bool success = false;

Chilkat.Email email = new Chilkat.Email();

// Add a PFX (or .p12) to be used for decryption
success = email.AddPfxSourceFile("myCert.p12","passwordForP12");
if (success != true) {
    Debug.WriteLine(email.LastErrorText);
    return;
}

// Loading the .eml automatically decrypts.
success = email.LoadEml("encrypted.eml");
if (success != true) {
    Debug.WriteLine(email.LastErrorText);
    return;
}

// The email now exists as it was prior to encryption.
// Your app may access the email's subject, body, attachments,
// etc. using the Chilkat Email API...

// Save the decrypted email:
success = email.SaveEml("decrypted.eml");
if (success != true) {
    Debug.WriteLine(email.LastErrorText);
    return;
}

Debug.WriteLine("Success.");