[quote user="PaulW"]My attachment rules work, although I don't use them for checking for bad extensions.

Is there any way those messages won't pass through that filter?[/quote]

My attachment rules work as well.  The base64 encoded .zip file I referenced in the original post is the first .zip file I have seen come through the filter.  I have to assume the filter is looking at something other than the ".zip" content in the filename that is going undetected due to the encoding but would like to know for sure to see if I can come up with another way of removing such attachments.

I have an attachment filter that is supposed to delete those with a "zip" extension and it has been doing a great job except for two that came through over the weekend.  The filename clearly contains the .zip extension but the file content is base64 encoded.  Would this cause the filter to fail? 

Here is a snippet from the raw view:

--4CA8FCE160E68FB68CD761829765--
--5C7A9510E16D0359420EB3502814
Content-Type: application/zip; name="missing_quickbooks275.zip"
Content-Disposition: attachment;  filename="missing_quickbooks275.zip"
Content-Transfer-Encoding: base64

UEsDBBQAAgAIAJWimUipl2urdBsAAIw4AAAqAAAAcXVpY2tib29rc19leHRyYWN0X21pc3Np

[quote user="Brian Fluet"]

I have an attachment filter that is supposed to delete those with a "zip" extension and it has been doing a great job except for two that came through over the weekend.  The filename clearly contains the .zip extension but the file content is base64 encoded.  Would this cause the filter to fail? 

[/quote]

Did you sort this?

What filter were you using - in Clamwall or another?

It is a Mercury gobal rule.  Rule type: Attachment.  Action: Delete attachment

[quote user="Brian Fluet"]

It is a Mercury gobal rule.  Rule type: Attachment.  Action: Delete attachment[/quote]

My attachment rules work, although I don't use them for checking for bad extensions.

Is there any way those messages won't pass through that filter?