(PureBasic) Send DKIM Signed Email

Demonstrates how to send DKIM signed email.

Chilkat PureBasic Module Download Chilkat PureBasic Module

IncludeFile "CkBinData.pb"
IncludeFile "CkDkim.pb"
IncludeFile "CkPrivateKey.pb"
IncludeFile "CkEmail.pb"
IncludeFile "CkMailMan.pb"

Procedure ChilkatExample()

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

    success.i
    mailman.i = CkMailMan::ckCreate()
    If mailman.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    dkim.i = CkDkim::ckCreate()
    If dkim.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    ; SMTP server settings...
    CkMailMan::setCkSmtpHost(mailman, "SMTP_DOMAIN")
    CkMailMan::setCkSmtpUsername(mailman, "SMTP_LOGIN")
    CkMailMan::setCkSmtpPassword(mailman, "SMTP_PASSWORD")
    CkMailMan::setCkSmtpPort(mailman, 465)
    CkMailMan::setCkSmtpSsl(mailman, 1)

    email.i = CkEmail::ckCreate()
    If email.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkEmail::setCkSubject(email, "This is a test")
    CkEmail::setCkBody(email, "This is a test")
    CkEmail::setCkFrom(email, "Chilkat Support <support@chilkatsoft.com>")

    ; Add some recipients (BCC recipients are added below)
    CkEmail::ckAddTo(email,"Chilkat Software","chilkat_software@yahoo.com")
    CkEmail::ckAddTo(email,"Chilkat Admin","admin@chilkatsoft.com")
    CkEmail::ckAddCC(email,"Chilkat Admin","admin@chilkat.io")

    ; When sending an email with a DKIM signature, the MIME
    ; of the email must not be modified prior to
    ; or during the sending process.  Therefore, the MIME of the
    ; email is assembled, the DKIM signature is added, and then
    ; SendMimeBd is called to send the email.

    ; First get the MIME of the email.  Calling RenderToMimeBd 
    ; causes the email to be signed and/or encrypted if those options
    ; have been selected.  The MIME returned by RenderToMimeBd
    ; 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...
    bdMime.i = CkBinData::ckCreate()
    If bdMime.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    success = CkMailMan::ckRenderToMimeBd(mailman,email,bdMime)
    If success <> 1
        Debug CkMailMan::ckLastErrorText(mailman)
        CkMailMan::ckDispose(mailman)
        CkDkim::ckDispose(dkim)
        CkEmail::ckDispose(email)
        CkBinData::ckDispose(bdMime)
        ProcedureReturn
    EndIf

    ; To create a DKIM signature,
    ; 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..
    CkDkim::setCkDkimDomain(dkim, "chilkatsoft.com")
    CkDkim::setCkDkimSelector(dkim, "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
    ; an empty password string argument, but it is ignored.
    password.s = "passwd"
    privKey.i = CkPrivateKey::ckCreate()
    If privKey.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    success = CkPrivateKey::ckLoadAnyFormatFile(privKey,"qa_data/pem/rsa_passwd.pem",password)
    If success <> 1
        Debug CkPrivateKey::ckLastErrorText(privKey)
        CkMailMan::ckDispose(mailman)
        CkDkim::ckDispose(dkim)
        CkEmail::ckDispose(email)
        CkBinData::ckDispose(bdMime)
        CkPrivateKey::ckDispose(privKey)
        ProcedureReturn
    EndIf

    success = CkDkim::ckSetDkimPrivateKey(dkim,privKey)
    If success <> 1
        Debug CkDkim::ckLastErrorText(dkim)
        CkMailMan::ckDispose(mailman)
        CkDkim::ckDispose(dkim)
        CkEmail::ckDispose(email)
        CkBinData::ckDispose(bdMime)
        CkPrivateKey::ckDispose(privKey)
        ProcedureReturn
    EndIf

    ; Add the DKIM-Signature header to the MIME in bdMime
    success = CkDkim::ckDkimSign(dkim,bdMime)
    If success <> 1
        Debug CkDkim::ckLastErrorText(dkim)
        CkMailMan::ckDispose(mailman)
        CkDkim::ckDispose(dkim)
        CkEmail::ckDispose(email)
        CkBinData::ckDispose(bdMime)
        CkPrivateKey::ckDispose(privKey)
        ProcedureReturn
    EndIf

    ; If desired, examine the MIME of the email being sent.
    CkBinData::ckWriteFile(bdMime,"qa_output/dkimSigned.eml")

    ; ---- Prepare to send the email contained in bdMime ---

    ; To send to multiple email addresses, the strRecipients should be set to a comma-separated
    ; list of email addresses.

    ; Note: This is where we can add additional BCC addreses.
    ; Here we are adding "chilkat.support@gmail.com" as an additional BCC address.
    ; Notice that the 1st three email addresses are NOT BCC because these email addresses
    ; appear in the MIME header of the email (in the "To" and "CC" header fields).
    ; A BCC email address does not appear in the MIME, and thus the non-BCC recipients cannot see
    ; that the email was also sent to the BCC address.  (BCC means "blind carbon copy")
    strRecipients.s = "chilkat_software@yahoo.com, admin@chilkatsoft.com, admin@chilkat.io, chilkat.support@gmail.com"
    strFrom.s = "support@chilkatsoft.com"

    success = CkMailMan::ckSendMimeBd(mailman,strFrom,strRecipients,bdMime)
    If success <> 1
        Debug CkMailMan::ckLastErrorText(mailman)
        CkMailMan::ckDispose(mailman)
        CkDkim::ckDispose(dkim)
        CkEmail::ckDispose(email)
        CkBinData::ckDispose(bdMime)
        CkPrivateKey::ckDispose(privKey)
        ProcedureReturn
    EndIf

    success = CkMailMan::ckCloseSmtpConnection(mailman)
    If success <> 1
        Debug "Connection to SMTP server not closed cleanly."
    EndIf

    Debug "DKIM Signed Mail Sent!"


    CkMailMan::ckDispose(mailman)
    CkDkim::ckDispose(dkim)
    CkEmail::ckDispose(email)
    CkBinData::ckDispose(bdMime)
    CkPrivateKey::ckDispose(privKey)


    ProcedureReturn
EndProcedure