On 6 Jun 2013, at 9:33, jayesh shinde wrote:
Hi ,
Is there any alternative , how to stop if spammer / virus infected
machine start sending such emails.
Due to this outlook's "On Behalf of" option , one of our end user
created the noise. This option makes confusion , when the end
recipient receive the emails and reply it.
I came to know in exchange this can be control from server side.
How the other experts are handling this kind of issue from server
side. I am searching the option by which postfix will allow SMTP
relay only if auth id + From: + Sender: are same.
Postfix itself delegates complex policy enforcement to add-on software.
For policies that require examination of message data (including
headers) beyond the very simple header_checks and body_checks
mechanisms, you can use any of the mechanisms documented in these files
that are part of the standard distribution and also are on the
postfix.org website:
FILTER_README: The "After-Queue" filter interface
SMTPD_PROXY_README: The "Before-Queue" filter interface
MILTER_README: The "Milter" interface (using the Sendmail-originated
Milter protocol)
As an immigrant from the Sendmail world, I have continued the MIMEDefang
Milter with Postfix for many years and haven't had any motivation to
switch. It would be easy to write the code for MIMEDefang to implement
your policy, if you have basic Perl competency. It is more common in the
Postfix world to use the amavisd-new filter, which I believe can use
either of the Postfix native interfaces and could be used to enforce
your policy. Both of those are commonly used as aggregators of other
packaged tools like anti-virus and anti-spam filters. Other Postfix
filters are available and it isn't unreasonable to consider writing your
own special-purpose filter for either of the native interfaces if you
have a good understanding of SMTP/RFC822 mail. I can't recommend writing
a Postfix filter to the Milter interface unless you have a need to hook
the same software into Sendmail.
