(Visual FoxPro) Send DKIM Signed Email

Demonstrates how to create a simple email, add a DKIM signature, and send it.

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

LOCAL loMailman
LOCAL loDkim
LOCAL loEmail
LOCAL lnSuccess
LOCAL loMimeData
LOCAL lcPassword
LOCAL loPrivKey
LOCAL loDkimSignedMime
LOCAL lcStrFrom
LOCAL lcStrTo

* 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.
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.MailMan')
loMailman = CreateObject('Chilkat.MailMan')

* The dkim object is used for creating the DKIM signature.
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.Dkim')
loDkim = CreateObject('Chilkat.Dkim')

* Set the SMTP server.
loMailman.SmtpHost = "smtp.chilkatsoft.com"

* Set the SMTP login/password (if required)
loMailman.SmtpUsername = "myUsername"
loMailman.SmtpPassword = "myPassword"
* Set the SmtpPort if your SMTP server uses an alternative port (default = 25)
loMailman.SmtpPort = 587

* Create a new email object
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.Email')
loEmail = CreateObject('Chilkat.Email')

loEmail.Subject = "This is a test"
loEmail.Body = "This is a test"
loEmail.From = "Chilkat Support <support@chilkatsoft.com>"
* We'll send the email to a Yahoo email account.  It is then
* possible to view the full headers within the Yahoo email
* interface to see if the DKIM signature was accepted.
lnSuccess = loEmail.AddTo("Chilkat Software","chilkat_software@yahoo.com")
lnSuccess = loEmail.AddTo("Chilkat Admin","admin@chilkatsoft.com")

* When sending an email with a DKIM signature, the MIME
* of the email must not be modified (in significant ways) prior to
* or during the sending process.  Therefore, the MIME of the
* email is assembled, the DKIM signature is added, and then
* SendMimeBytes is called to send the email.

* Get the MIME of the email.  Calling RenderToMimeBytes 
* causes the email to be signed and/or encrypted if those options
* have been selected.  The MIME returned by RenderToMimeBytes
* is the exact MIME that would've been sent if SendEmail was
* called.  We'll add a DKIM signature header to this MIME and then send...

loMimeData = loMailman.RenderToMimeBytes(loEmail)
IF (loMailman.LastMethodSuccess <> 1) THEN
    ? loMailman.LastErrorText
    RELEASE loMailman
    RELEASE loDkim
    RELEASE loEmail
    CANCEL
ENDIF

* To create a DKIM signature for email (i.e. MIME),
* you'll need to provide the following:
* (1) An RSA private key in any common file format.
* (2) The domain name (typically the same domain
* as the sender of an email).
* (3) A selector for the domain name -- an arbitrary string
* to identify the matching public key in DNS.

* To allow an email recipient to verify the DKIM signature via an
* external email client supporting DKIM or using other software,
* you will need to create a DNS record with the selector
* and matching public key.  This example does not provide
* information about DKIM DNS record creation.  
* (Chilkat does not provide an API for creating DNS records.  
* Creating the DKIM DNS record is something you would do
* manually.)

* Set the domain and selector:
* You'll need to provide your own values here..
loDkim.DkimDomain = "chilkatsoft.com"
loDkim.DkimSelector = "brisbane"

* Load a private key from any common RSA private key
* format, such as DER, PKCS8, PEM, XML, etc.
* The LoadDkimPkFile method automatically detects
* the file format and reads it appropriately.
* If a password is not required, you'll still need to provide
* a password string argument, but it is ignored.
lcPassword = "optionalPassword"
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.PrivateKey')
loPrivKey = CreateObject('Chilkat.PrivateKey')
lnSuccess = loPrivKey.LoadAnyFormatFile("myPrivateKey.pem",lcPassword)
IF (lnSuccess <> 1) THEN
    ? loPrivKey.LastErrorText
    RELEASE loMailman
    RELEASE loDkim
    RELEASE loEmail
    RELEASE loPrivKey
    CANCEL
ENDIF

lnSuccess = loDkim.SetDkimPrivateKey(loPrivKey)
IF (lnSuccess <> 1) THEN
    ? loDkim.LastErrorText
    RELEASE loMailman
    RELEASE loDkim
    RELEASE loEmail
    RELEASE loPrivKey
    CANCEL
ENDIF

* Add the DKIM-Signature header and
* returns the new MIME with DKIM-Signature added.

loDkimSignedMime = loDkim.AddDkimSignature(loMimeData)
IF (loDkim.LastMethodSuccess <> 1) THEN
    ? loDkim.LastErrorText
    RELEASE loMailman
    RELEASE loDkim
    RELEASE loEmail
    RELEASE loPrivKey
    CANCEL
ENDIF

* Call SendMimeBytes to connect to the SMTP server and send.
* The connection (i.e. session) to the SMTP server remains
* open so that subsequent Send* calls may use the
* same connection.  
lcStrFrom = "support@chilkatsoft.com"
* To send to multiple email addresses, the strTo should be set to a comma-separated
* list of email addresses.
lcStrTo = "chilkat_software@yahoo.com, admin@chilkatsoft.com"
lnSuccess = loMailman.SendMimeBytes(lcStrFrom,lcStrTo,loDkimSignedMime)
IF (lnSuccess <> 1) THEN
    ? loMailman.LastErrorText
    RELEASE loMailman
    RELEASE loDkim
    RELEASE loEmail
    RELEASE loPrivKey
    CANCEL
ENDIF

* Some SMTP servers do not actually send the email until 
* the connection is closed.  In these cases, it is necessary to
* call CloseSmtpConnection for the mail to be  sent.  
* Most SMTP servers send the email immediately, and it is 
* not required to close the connection.  We'll close it here
* for the example:
lnSuccess = loMailman.CloseSmtpConnection()
IF (lnSuccess <> 1) THEN
    ? "Connection to SMTP server not closed cleanly."
ENDIF

? "DKIM Signed Mail Sent!"

RELEASE loMailman
RELEASE loDkim
RELEASE loEmail
RELEASE loPrivKey