Sometimes, like in the case of an email migration, it is necessary to wait for DNS changes (MX records for example) to replicate before continuing your migration, otherwise mail might bounce or other nastiness may occur.
The following VB Script runs in a loop and monitors a DNS record, in this case an MX record, for an expected new value. Once the value is returned the script will send an email. This is great if you want to make an MX record change, then go to dinner while you wait for your ISP’s changes to replicate, then send you an email once it’s returning the correct value.
Simply change the top 2 highlighted entries to identify the MX record value you expect from the NSLOOKUP, and the other highlighted portions to define the SMTP relay you should use, reply-to address and recipient email.
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Set oShell = CreateObject(“Wscript.Shell”)
Set oExec = oShell.Exec(“nslookup -type=mx contoso.com“)
Do
Dim CheckStatus
CheckStatus = oExec.Status
Do Until oExec.StdOut.AtEndOfStream
strLine = oExec.StdOut.ReadLine()
If InStr (strLine,”MX preference”) <> 0 Then
If InStr (strLine,”contoso.com“) <> 0 Then
strMXChanged = “MX record for contoso.com has changed”
SendMail “admin.user@contoso.com“, strMXChanged
Exit Do
End If
End If
Loop
If CheckStatus <> 0 Then Exit Do
Loop
Sub SendMail(strTO, strMXChanged)
Dim iMsg
Dim iConf
Dim Flds
Dim strHTML
Dim strSmartHost
Const cdoSendUsingPort = 2
StrSmartHost = “mail.contoso.corp“
set iMsg = CreateObject(“CDO.Message”)
set iConf = CreateObject(“CDO.Configuration”)
Set Flds = iConf.Fields
‘ set the CDOSYS configuration fields to use port 25 on the SMTP server
With Flds
.Item(“http://schemas.microsoft.com/cdo/configuration/sendusing“) = cdoSendUsingPort
.Item(“http://schemas.microsoft.com/cdo/configuration/smtpserver“) = strSmartHost
.Item(“http://schemas.microsoft.com/cdo/configuration/smtpconnectiontimeout“) = 10
.Update
End With
‘ build HTML for message body
strMSG = “Record changed”
‘ apply the settings to the message
With iMsg
Set .Configuration = iConf
.To = strTO
.From = “MX-alert@contoso.com“
.Subject = strMXChanged
.TEXTBody = strMSG
.Send
End With
‘ cleanup of variables
Set iMsg = Nothing
Set iConf = Nothing
Set Flds = Nothing
End Sub