On Fri, Jun 13, 2014 at 11:03 AM, Tony Finch <dot(_at_)dotat(_dot_)at> wrote:
Phillip Hallam-Baker <phill(_at_)hallambaker(_dot_)com> wrote:
At the moment the mail systems make no distinction between someone
outside
my company sending me a ZIP file and me sending a ZIP file to my
engineers.
That is due to the mail protocols being defective.
No, that's poor configuration by your postmasters. It's straightforward
and quite common to configure distinct security policies for internal and
external mail, based on whether the message arrived via your submission
service or your MX service.
Actually it is quite a bit more complicated than that and has to do with
being a security company and the difference between what we think is
correct and what we can prove to our auditors at reasonable cost.