We recently upgraded to ZCS 6.0.7 NE. All seems to be well, with one big problem (for us anyway). The attachment filtering works a little too well.
Our organization needs to be able to send and receive otherwise banned content (exe,bat,dll, etc...) via a password encrypted ZIP archive. We have disabled the blocking of encrypted archives, but that does not allow us to send anything in the banned content list via an encrypted ZIP. It would appear that Zimbra (via Amavis?) is doing a regex search against the contents of the zip, and blocking the content, regardless of the password encrypted ZIP file. If I double ZIP the contents, with the outermost ZIP being password encrypted, we can pass the content through. Renaming a ZIP to .txt doesn't help since the filters seem to use file to determine the type, rather than the extension.
I understand why this is cool for most organizations, and we obviously want banned content to get blocked under other circumstances. How do we configure the system to allow encrypted ZIP files that contain otherwise banned content? Is there a configuration option or combination of options within Amavis or somewhere else that we should look?
Thanks for any assistance with this issue.