I am talking about the mail content, and I'm using S/MIME. Yes, I'm sure the accountant will never send me unencrypted mail.
Thanks, On 6 January 2011 14:25, Ansgar Wiechers <li...@planetcobalt.net> wrote: > On 2011-01-06 IT geek 31 wrote: >> My accountant and I both have digital certificates and most of the >> time encrypt our mails. But he often forgets, meaning sensitive >> information is sent in plaintext. >> >> Is there any way to instruct Postfix to reject his mail unless it is >> encrypted? >> >> I know I can setup TLS, but that is something I don't want to do just >> yet. >> >> Any ideas? > > I'm going to assume that you're talking about encrpyting the mail > content for either outbound or internal mail. TLS won't help you there, > because it encrypts only the connection to the next HOP, not end-to-end. > > What technology are you using? GPG/PGP or S/MIME? For GPG a friend of > mine and myself wrote a simple encrypting proxy [1] (I suppose it could > be adapted for S/MIME). The Proxy will drop all recipients for whom no > encryption key exists from the mail. It will drop the mail altogether, > if none of the recipients have an encryption key. Are you positive that > your accountant will never have to send unencrypted mail? > > [1] http://www.planetcobalt.net/download/crypter.pl > > Regards > Ansgar Wiechers > -- > "Abstractions save us time working, but they don't save us time learning." > --Joel Spolsky >
