(Xojo Plugin) 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 Xojo Plugin Download Xojo Plugin for Windows, Linux, Mac OS X, and ARM, ARM64

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

Dim mailman As New Chilkat.MailMan

// SMTP connection settings...
mailman.SmtpHost = "smtp.example.com"
mailman.SmtpUsername = "MY_SMTP_USERNAME"
mailman.SmtpPassword = "MY_SMTP_PASSWORD"
mailman.SmtpSsl = True
mailman.SmtpPort = 465

// Create a new email object
Dim email As New Chilkat.Email

email.Subject = "This is a test"
email.Body = "This is a test"
email.From = "myemail@example.com"
Dim success As Boolean
success = email.AddTo("person1","person1@example.com")
success = email.AddTo("person2","person2@example.com")
success = email.AddTo("person3","person3@example.com")
// The SMTP server smtp.example.com won't know anything about an email address @somewhere_else.com
success = email.AddTo("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.)
Dim badAddrs As New Chilkat.StringArray
success = mailman.VerifyRecips(email,badAddrs)
If (success <> True) Then
    System.DebugLog(mailman.LastErrorText)
    Return
End If

Dim i As Int32
i = 0
While i < badAddrs.Count
    System.DebugLog(badAddrs.GetString(i))
    i = i + 1
Wend

System.DebugLog("done.")