Mark Nottingham:
> Hi,
>
> I?d like to insert SMTP headers and/or body content (e.g., using alterMIME)
> in outgoing e-mails *if* the SMTP connection to the recipient is not
> protected by TLS.
>
> Is this possible in postfix today, or would it require a change to source?
No, you add the headers with a policy daemon, a Milter, or with
an SMTP-based content filter.
With a policy daemon in smtpd_data_restrictions, use the PREPEND
action to add a header when the encryption_protocol, encryption_cipher
or encryption_keysize attributes are empty. postfwd might have
all that you need.
Milters are available in Python, Perl, C, Java, and probably more
languages. Just look at your Postfix's Received: header, assuming
that you have "smtpd_tls_received_header = yes". You may also
be interested in "smtpd_sasl_authenticated_header = yes".
Wietse
