(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.

Chilkat PureBasic Module Download Chilkat PureBasic Module

IncludeFile "CkStringArray.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.

    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.i = 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