We have an solution design that will be sending Encrypted PDF's to our many clients, who will all be using varied email providers.
We have tested the pdf's through the usual cast of internet mail providers, and to my surprise they are not blocked.
I believe that this is dangerous and I suspect that encrypted content may be blocked routinely by mail gateways in future, because virus scanners cannot verify if there is malware in the file. So these services fail-open vs fail-closed when observing these PDFs.
What do you-all think? Is this a danger? Has anyone else had this problem?
I am quite frankly surprised by this behavior.