Sunday, May 09, 2010

Quck SMTP Bandwidth usage script for Exchange 2007

Being able to tell how much bandwidth a particular server has consumed over a period of time is quite handy when your in a pinch and trying to work out where your bandwidth is being consumed. It can also be used in a wider context when trying to work what particular patterns and pressures are happening on particular server. The latter requiring a a more lateral analysis of the data.

Exchange 2007 does a good job of logging message tracking information but these create a chalenge of filtering down this information into what been sent/received and how much bandwidth being used.

The first things this script does is grabs all the message tracking records for a particular time period for a paricular server (based on a cmdline parameter you pass it). It then filters just on Sent and Recieved Email and then uses a hashtable and some other filtering code to count the number of email sent and recieved based on recpients of a message (eg a message sent to 5 external recipients will be count 5 times).

How accurate is this well ..... its approximatly acurate the data is good but some better maths is need to get a really acurate but thats a longer story that would probably put you all to sleep ...

To run the script you need to provide the servername of the server you want to pull the logs from and the number of hours you want to look back eg to look at the last 24 hours on a server call myexserver would be

./lexchv2.ps1 myexserver 24

I've put a download of the script here the code looks like

$dtQueryDT = [system.DateTime]::Now.AddHours(-($args[1]))
$dtQueryDTf = [system.DateTime]::Now

$InternalNum = 0
$InternalSize = 0

$ExternalSentNum = 0
$ExternalSentSize = 0

$ExternalRecNum = 0
$ExternalRecSize = 0

$ServerName = $args[0]

$DomainHash = @{}
$msgIDArray = @{}

get-accepteddomain | ForEach-Object{
if ($_.DomainType -eq "Authoritative"){


Get-MessageTrackingLog -Server $ServerName -ResultSize Unlimited -Start $dtQueryDT -End $dtQueryDTf | ForEach-Object{
if ($_.EventID.ToString() -eq "SEND" -bor $_.EventID.ToString() -eq "RECEIVE"){
foreach($recp in $_.recipients){
if($recp.ToString() -ne ""){
$unkey = $recp.ToString() + $_.Sender.ToString() + $_.MessageId.ToString()
if ($msgIDArray.ContainsKey($unkey) -eq $false){
$recparray = $recp.split("@")
$sndArray = $_.Sender.split("@")
if ($_.Sender -ne ""){
if ($DomainHash.ContainsKey($recparray[1])){
if ($DomainHash.ContainsKey($sndArray[1])){
$InternalNum = $InternalNum + 1
$InternalSize = $InternalSize + $_.TotalBytes/1024

$ExternalRecNum = $ExternalRecNum + 1
$ExternalRecSize = $ExternalRecSize + $_.TotalBytes/1024
if ($DomainHash.ContainsKey($sndArray[1])){
$ExternalSentNum = $ExternalSentNum + 1
$ExternalSentSize = $ExternalSentSize + $_.TotalBytes/1024



"Sent/Recieved Internally Number : " + $InternalNum
"Sent/Recieved Internally Size : " + [math]::round($InternalSize/1024,2)
"Externally Sent Number : " + $ExternalSentNum
"Externally Sent Size : " + [math]::round($ExternalSentSize/1024,2)
"Externally Recieved Number : " + $ExternalRecNum
"Externally Recieved Size : " + [math]::round($ExternalRecSize/1024,2)