On 21 Oct 2019, at 7:13, Jayesh Shinde wrote:
Hi ,
For identifying external world & spoof emails , I am looking for
solution where we can add notification / warning banner in email body
like below .
"_This e-mail is received from external domain. Please review before
opening any attachment or link_"
This will help end user to identify risk while reply or URL click .
Is there any milter or postfix solution available where we can set
condition and then above warning will get append at the starting of
email ?
or is there any way to append disclaimer at the starting of email ? I
checked alterMIME & MailScanner which are adding disclaimer at the
bottom of
email , I am looking to add it on starting of email.
The best way to do this with any tool you might use would be to wrap the
incoming message in an encapsulating multipart/mixed MIME object with
your warning banner in a first text/plain part and the original message
in a message/rfc822 part. This has the advantage of preserving
legitimate messages intact, including its original MIME structure,
headers, and any cryptographic signatures. Different MUAs will present
that construct in different ways to users but it is broadly supported.
The best existing tool for this would be MIMEDefang. It is a milter that
has optional hooks for multiple anti-virus tools as well as
SpamAssassin, however at its core is a wrapper for the Perl MIME-Tools
suite, which can manipulate mail messages as MIME structures in any way
that you would like. The prerequisites are that you need to understand
the basic concepts of MIME structure and have basic Perl programming
skill, since the main configuration file is a collection of Perl
subroutines called by the MIMEDefang milter at the various stages of
milter<->MTA interaction.
--
Bill Cole
b...@scconsult.com or billc...@apache.org
(AKA @grumpybozo and many *@billmail.scconsult.com addresses)
