Block 2000+ Distribution List's from External Email

1 option is to search for groups with exchange email addresses in AD users and computers, select all of the groups, and get the properties, and edit the Exchange General tab and accept messages from authenticated users only.

Another option which will keep the spam OFF of your network, is to get a third party service such as Postini.  That way the spam never gets on your network at all and saves you bandwidth, CPU, etc.

I am pretty sure that admodify.net will allow you to make the changes in bulk.

http://www.codeplex.com/admodify

Simon.

@ zelron22.  I'm unable to do this.  If I do a search for them I am unable to select multiple entries and select properties.  If I navigate through ADUC and select multiple entries and click Properties the only tab I have is General.  Also, we are using Postini but we would also like to block off the DL's from external emails as Postini let's new forms of spam through.  Plus we would still have to add the DL's to Postini.

@ Mestha.  Thanks, this looks like a nice utility.  However, when I queried my main Domain the application encountered an error and asked me if I wanted to continue.  Since this is a production environment that can't risk being taken down I'm hesitant to use this application.  Thanks though.

Also, I guess I underestimated.  We have about 7000 DL's. As you can imagine this makes it more difficult.  So is there a way to query AD, generate a list of all the distribution lists and create a bat file (possibly from an Excel spreadsheet) that can apply the changes I need?

Thanks zelron, we got it setup using Postini instead of blocking off the DL's completely.