PureBasic

Verify Email Recipients

A way to possibly determine valid/invalid email addresses. I would recommend being very careful about doing this because your IP address may be flagged as a potential spammer by the mail server (because you are probing for valid/invalid email addresses). This Chilkat functionality existed for many years, before this kind of activity became a problem. The functionality remains only because it is useful for some to test with their own SMTP servers. PureBasic

IncludeFile "CkStringArray.pb"
IncludeFile "CkEmail.pb"
IncludeFile "CkMailMan.pb"

Procedure ChilkatExample()

    success.i = 0

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

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

    ; SMTP connection settings...
    CkMailMan::setCkSmtpHost(mailman, "smtp.example.com")
    CkMailMan::setCkSmtpUsername(mailman, "MY_SMTP_USERNAME")
    CkMailMan::setCkSmtpPassword(mailman, "MY_SMTP_PASSWORD")
    CkMailMan::setCkSmtpSsl(mailman, 1)
    CkMailMan::setCkSmtpPort(mailman, 465)

    ; Create a new email object
    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, "myemail@example.com")
    success = CkEmail::ckAddTo(email,"person1","person1@example.com")
    success = CkEmail::ckAddTo(email,"person2","person2@example.com")
    success = CkEmail::ckAddTo(email,"person3","person3@example.com")
    ; The SMTP server smtp.example.com won't know anything about an email address @somewhere_else.com
    success = CkEmail::ckAddTo(email,"person3","person4@somewhere_else.com")
    ; ...

    ; Verify recipients.
    ; **** See the warning about using this API method in the description above.
    ; (An SMTP server only knows valid email address for its own domain.  For example,
    ; smtp.example.com *may* only know if person1@example.com is valid or invalid, but does
    ; not know anything about the validity of email addresses having other domains.)
    badAddrs.i = CkStringArray::ckCreate()
    If badAddrs.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    success = CkMailMan::ckVerifyRecips(mailman,email,badAddrs)
    If success <> 1
        Debug CkMailMan::ckLastErrorText(mailman)
        CkMailMan::ckDispose(mailman)
        CkEmail::ckDispose(email)
        CkStringArray::ckDispose(badAddrs)
        ProcedureReturn
    EndIf

    i.i = 0
    While i < CkStringArray::ckCount(badAddrs)
        Debug CkStringArray::ckGetString(badAddrs,i)
        i = i + 1
    Wend

    Debug "done."


    CkMailMan::ckDispose(mailman)
    CkEmail::ckDispose(email)
    CkStringArray::ckDispose(badAddrs)


    ProcedureReturn
EndProcedure