Wednesday, July 18, 2007

Turning on Filter Junk Email in Exchange 2007 via an OWA Script

In the past I’ve posted a few scripts for setting and reading the OWA junk email filter settings here. While content filtering and the IMF have changed in Exchange 2007 there are still no cmdlets that will allow you to flip this option on or off for users so this little script still can come in handy for various situations. Because OWA was rewritten from the ground up in Exchange 2007 the old script method no longer works. However the same methods of reverse engineering the OWA method do work with a few additions.

Using the MSXML2.ServerXMLHTTP.6.0 object this object is included with the Microsoft XML Parser (MSXML) and is a better choice for this script because it firstly supports the ability to ignore any SSL errors that might happen (eg self signed Certs, Alternate names etc) and it also handles dealing with the Forms Based Authentication cookie without the necessity to add additional code. The code still needs to perform the synthetic forms logon this works similar to 2003 with a few URL tweaks.

Dealing with the Language form for users who have never logged on to OWA before. Because this script is simulating a user in OWA if the mailbox your trying to set the junk email settings has never been logged onto before in OWA then the default language form will be presented to the user (or the script in this case) asking the person to choose there timezone and language. What this script does to cater for this is that it looks for this form in the response if it finds the form it then uses 2 regular expressions to parse the default values from the form and then posts these values. One problem this creates is that the user will nolonger be shown this form when they first logon anymore this may or may not be a problem for you. If you need for this form to still appear at first logon there are two options the first is to delete the OWA storage object in the root of the mailbox using WebDAV or Neil Hobson posted another method on the Exchange Blog.

The operation of the script is pretty simple after logging in it tries to post to the following URL QueryString in the Target Mailbox “/ev.owa?oeh=1&ns=JunkEmail&ev=Enable” with a body

"<params><fEnbl>1</fEnbl></params>"

This will enable junk email filtering on a mailbox to disable junk email filtering use

"<params><fEnbl>0</fEnbl></params>"

To use this script you need to hard code the username and password of a user that has been give delegate access to the target mailbox using something like this in the Exchange Command Shell

Add-MailboxPermission –Identity ‘Mailbox’ –User ‘User’ –AccessRights FullAccess

Or has been given Send As and Receive As rights on the target mailbox. Basically the user needs to be able to open the target mailbox as another mailbox in OWA you can test if the account you want to use is going to be work by testing this yourself in OWA. Its also important that the account that you want to use has logged onto OWA once as well this is because the Language form would be presented to this user the first time the user tries to logon to OWA while the script caters for this for the target user it doesn’t do it for the source so this would cause a timeout error in the case the source user has never logged on to OWA. So before using the script you need to configure the following variables

snServername = "ServerName"
mnMailboxname = "mailbox"
domain = "domain"
strpassword = "password"

In the snServername variable make sure you use the servername of your CAS server this may or may not be different from your mailbox server.

The following variable is for the target mailbox you want to set the junkemail setting on this should be the primary SMTP address of the target mailbox

Targetmailbox = "user@domain.com"

The scripts output is pretty verbose you should see the full response headers outputted for each request the script make this helps if you ever need to diagnose why the script isn’t working

I’ve put a downloadable copy of the script here the script itself looks like

snServername = "ServerName"
mnMailboxname = "mailbox"
domain = "domain"
strpassword = "password"

strusername = domain & "\" & mnMailboxname
szXml = "destination=https://" & snServername & "/owa/&flags=0&username=" &
strusername
szXml = szXml & "&password=" & strpassword & "&SubmitCreds=Log On&forcedownlevel=0&trusted=0"


set req = createobject("MSXML2.ServerXMLHTTP.6.0")
req.Open "post", "https://" & snServername & "/owa/auth/owaauth.dll", False
req.SetOption 2, 13056
req.send szXml

reqhedrarry = split(req.GetAllResponseHeaders(), vbCrLf,-1,1)
for each ent in reqhedrarry
wscript.echo ent
Next

Call UpdateJunk("user@domain.com")

Sub UpdateJunk(mbMailbox)

xmlstr = "<params><fEnbl>1</fEnbl></params>"

req.Open "POST", "https://" & snServername & "/owa/" & mbMailbox & "/ev.owa?oeh=1&ns=JunkEmail&ev=Enable",
False
req.setRequestHeader "Content-Type", "text/xml; charset=""UTF-8"""
req.setRequestHeader "Content-Length", Len(xmlstr)
req.send xmlstr
wscript.echo req.status
reqhedrarry = split(req.GetAllResponseHeaders(), vbCrLf,-1,1)
for each ent in reqhedrarry
wscript.echo ent
Next
If InStr(req.responsetext,"name=lngFrm") Then
wscript.echo "Mailbox has not been logged onto before via OWA"
'Create a regular expression object
Dim objRegExp
Set objRegExp = New RegExp

'Set our pattern
objRegExp.Pattern = "<option selected value=""(.*?)"">"
objRegExp.IgnoreCase = True
objRegExp.Global = True

Dim objMatches
Set objMatches = objRegExp.Execute(req.responsetext)
If objMatches.count = 2 then
lcidarry = Split(objMatches(0).Value,Chr(34))
wscript.echo lcidarry(1)
tzidarry = Split(objMatches(1).Value,Chr(34))
wscript.echo tzidarry(1)
pstring = "lcid=" & lcidarry(1) & "&tzid=" & tzidarry(1)
req.Open "POST", "https://" & snServername & "/owa/" & mbMailbox & "/lang.owa",
False
req.setRequestHeader "Content-Type", "application/x-www-form-urlencoded"
req.setRequestHeader "Content-Length", Len(pstring)
' req.SetRequestHeader "cookie", reqCadata
req.send pstring
if instr(req.responsetext,"errMsg") then
wscript.echo "Permission Error"
else
wscript.echo req.status
If req.status = 200 and not instr(req.responsetext,"errMsg") Then
Call UpdateJunk(mbMailbox)
Else
wscript.echo "Failed to set Default OWA settings"
End if
end if

Else
wscript.echo "Script failed to retrieve default values"
End if
Else
wscript.echo "Junk Mail Setting Updated"
End if
End sub