Send DKIM Signed Email

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

Note: Requires version 9.0.3 or greater (or v7.9.5 or greater of the Email ActiveX).

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CREATE PROCEDURE ChilkatSample
AS
BEGIN
    DECLARE @hr int
    DECLARE @sTmp0 nvarchar(4000)
    --  This example uses the Chilkat MIME/DKIM component
    --  for adding a DKIM signature, and the Chilkat Email
    --  component for creating and sending the email.

    --  The mailman object is used for sending and receiving email.
    --  The mailman object is part of the Chilkat Email product.
    DECLARE @mailman int
    EXEC @hr = sp_OACreate 'Chilkat.MailMan2', @mailman OUT
    IF @hr <> 0
    BEGIN
        PRINT 'Failed to create ActiveX component'
        RETURN
    END

    --  Any string argument automatically begins the 30-day trial.
    DECLARE @success int

    EXEC sp_OAMethod @mailman, 'UnlockComponent', @success OUT, '30-day trial'
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @mailman, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        RETURN
      END

    --  The dkim object is used for creating the DKIM signature.
    --  It belongs to the "Chilkat MIME" product.
    DECLARE @dkim int
    EXEC @hr = sp_OACreate 'Chilkat.Dkim', @dkim OUT
    IF @hr <> 0
    BEGIN
        PRINT 'Failed to create ActiveX component'
        RETURN
    END

    EXEC sp_OAMethod @dkim, 'UnlockComponent', @success OUT, 'Anything for 30-day trial'
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @dkim, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        RETURN
      END

    --  Set the SMTP server.
    EXEC sp_OASetProperty @mailman, 'SmtpHost', 'smtp.chilkatsoft.com'

    --  Set the SMTP login/password (if required)
    EXEC sp_OASetProperty @mailman, 'SmtpUsername', 'myUsername'
    EXEC sp_OASetProperty @mailman, 'SmtpPassword', 'myPassword'
    --  Set the SmtpPort if your SMTP server uses an alternative port (default = 25)
    EXEC sp_OASetProperty @mailman, 'SmtpPort', 587

    --  Create a new email object
    DECLARE @email int
    EXEC @hr = sp_OACreate 'Chilkat.Email2', @email OUT
    IF @hr <> 0
    BEGIN
        PRINT 'Failed to create ActiveX component'
        RETURN
    END

    EXEC sp_OASetProperty @email, 'Subject', 'This is a test'
    EXEC sp_OASetProperty @email, 'Body', 'This is a test'
    EXEC sp_OASetProperty @email, '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.
    EXEC sp_OAMethod @email, 'AddTo', NULL, 'Chilkat Software', 'chilkat_software@yahoo.com'
    EXEC sp_OAMethod @email, 'AddTo', NULL, '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...

    EXEC sp_OAMethod @mailman, 'RenderToMimeBytes', @mimeData OUT, @email

    --  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..
    EXEC sp_OASetProperty @dkim, 'DkimDomain', 'chilkatsoft.com'
    EXEC sp_OASetProperty @dkim, '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.
    DECLARE @password nvarchar(4000)

    SELECT @password = 'optionalPassword'
    EXEC sp_OAMethod @dkim, 'LoadDkimPkFile', @success OUT, 'myPrivateKey.pem', @password
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @dkim, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        RETURN
      END

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

    EXEC sp_OAMethod @dkim, 'AddDkimSignature', @dkimSignedMime OUT, @mimeData

    --  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.
    DECLARE @strFrom nvarchar(4000)

    SELECT @strFrom = 'support@chilkatsoft.com'
    --  To send to multiple email addresses, the strTo should be set to a comma-separated
    --  list of email addresses.
    DECLARE @strTo nvarchar(4000)

    SELECT @strTo = 'chilkat_software@yahoo.com, admin@chilkatsoft.com'
    EXEC sp_OAMethod @mailman, 'SendMimeBytes', @success OUT, @strFrom, @strTo, @dkimSignedMime
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @mailman, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        RETURN
      END

    --  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:
    EXEC sp_OAMethod @mailman, 'CloseSmtpConnection', @success OUT
    IF @success <> 1
      BEGIN
        PRINT 'Connection to SMTP server not closed cleanly.'
      END

    PRINT 'DKIM Signed Mail Sent!'
END
GO