Phillip Hallam-Baker <phill@xxxxxxxxxxxxxxx> 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. Tony. -- f.anthony.n.finch <dot@xxxxxxxx> http://dotat.at/ Humber: Northwest, veering northeast, 3 or 4. Smooth, becoming slight or moderate. Fog patches for a time. Moderate or good, occasionally very poor.