We had an interesting issue recently where our Exchange 2010 Edge Transport server was erroneously stripping out .zip files. The funny thing was that we really didn’t intend for it to be doing attachment filtering in the first place as we have a variety of other tools in place to take care of that. It’s enabled by default though, and I wanted it off, so we needed to add an exception for our receive connector.
It’s not as straightforward as you would expect though to turn off attachment filtering on an Exchange 2010 Edge Transport server.
The first step is to see if there are any connectors on the attachment filter exception list presently. To do so, run this command:
About the fifth line down you should see “ExceptionConnectors” which probably has nothing next to it. Even if it does, it really doesn’t matter, we’re just checking so that we know the current state of affairs (always best to know your starting point so that you can check again at the end and make sure you were successful with what you think you did).
You can only turn off attachment filtering by referencing the GUID, so now we need to get the GUID of the relevant receive connector. In our situation, the connector’s name was “Inbound from Internet,” so we run this command:
Get-ReceiveConnector "Inbound from Internet" | Format-List
This will give us all the properties of our Receive Connector, including the GUID, which will be listed about 10 lines up from the bottom.
Now that we have the GUID, we can run the command to add the receive connector to the list of exceptions for attachment filtering by running this:
Set-AttachmentFilterListConfig –ExceptionConnectors [GUID]
Replacing [GUID] with the GUID we retrieved in the previous step.
Finally, run Get-AttachmentFilterListConfig again and check the Exceptions line, you should now see your receive connector listed there.