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DataFlex

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 DataFlex Downloads

DataFlex
Use ChilkatAx-win32.pkg

Procedure Test
    Boolean iSuccess
    Handle hoMailman
    Variant vEmail
    Handle hoEmail
    Variant vBadAddrs
    Handle hoBadAddrs
    Integer i
    String sTemp1

    Move False To iSuccess

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

    Get Create (RefClass(cComChilkatMailMan)) To hoMailman
    If (Not(IsComObjectCreated(hoMailman))) Begin
        Send CreateComObject of hoMailman
    End

    // SMTP connection settings...
    Set ComSmtpHost Of hoMailman To "smtp.example.com"
    Set ComSmtpUsername Of hoMailman To "MY_SMTP_USERNAME"
    Set ComSmtpPassword Of hoMailman To "MY_SMTP_PASSWORD"
    Set ComSmtpSsl Of hoMailman To True
    Set ComSmtpPort Of hoMailman To 465

    // Create a new email object
    Get Create (RefClass(cComChilkatEmail)) To hoEmail
    If (Not(IsComObjectCreated(hoEmail))) Begin
        Send CreateComObject of hoEmail
    End

    Set ComSubject Of hoEmail To "This is a test"
    Set ComBody Of hoEmail To "This is a test"
    Set ComFrom Of hoEmail To "myemail@example.com"
    Get ComAddTo Of hoEmail "person1" "person1@example.com" To iSuccess
    Get ComAddTo Of hoEmail "person2" "person2@example.com" To iSuccess
    Get ComAddTo Of hoEmail "person3" "person3@example.com" To iSuccess
    // The SMTP server smtp.example.com won't know anything about an email address @somewhere_else.com
    Get ComAddTo Of hoEmail "person3" "person4@somewhere_else.com" To iSuccess
    // ...

    // 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.)
    Get Create (RefClass(cComCkStringArray)) To hoBadAddrs
    If (Not(IsComObjectCreated(hoBadAddrs))) Begin
        Send CreateComObject of hoBadAddrs
    End
    Get pvComObject of hoEmail to vEmail
    Get pvComObject of hoBadAddrs to vBadAddrs
    Get ComVerifyRecips Of hoMailman vEmail vBadAddrs To iSuccess
    If (iSuccess <> True) Begin
        Get ComLastErrorText Of hoMailman To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Move 0 To i
    While (i < (ComCount(hoBadAddrs)))
        Get ComGetString Of hoBadAddrs i To sTemp1
        Showln sTemp1
        Move (i + 1) To i
    Loop

    Showln "done."


End_Procedure