(VB.NET) MX Lookup Mail Server Domain by Email Address

How to find the mail server for a given email address. Returns the domain name of the primary mail server.

Note: This example requires Chilkat v11.0.0 or greater.

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Dim success As Boolean = False

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

Dim dns As New Chilkat.Dns
Dim json As New Chilkat.JsonObject

Dim emailAddr As String = "bob@example.com"

' This gets all MX domains for an email address.  (Typically one domain.)
' The preferred domain will be at index 0 (see below).
success = dns.Query("MX",emailAddr,json)
If (success = False) Then
    Debug.WriteLine(dns.LastErrorText)
    Exit Sub
End If


Dim i As Integer = 0
Dim count_i As Integer = json.SizeOfArray("answer.mx")
While i < count_i
    json.I = i
    Dim domain As String = json.StringOf("answer.mx[i].domain")
    Debug.WriteLine(domain)
    i = i + 1
End While