Message transport policies

[Andrew]

Hi to all! Just a simple question...

Is it possible with Sendmail (8.13.8) to do basic mail filtering and/or
routing, basing on specific rules, as Exchange Server 2007 allows me to
define, in order to enforce corporate/legal policies on e-mail traffic?

For example, I would accept messages sent to a specific internal e-mail
address (public...@internal.com) only if the sender address belongs in a
specific domain (*@news.external.com).

Another example: I would send a copy of any message sent to a specific
external recipient (som...@external.com) to the postmaster's address.

Can I do something like this with Sendmail? I have to install any add-ons
to accomplish this?

TIA

Andrew

[Grant Taylor]

Andrew wrote:
> For example, I would accept messages sent to a specific internal e-mail
> address (public...@internal.com) only if the sender address belongs in a
> specific domain (*@news.external.com).
>
> Another example: I would send a copy of any message sent to a specific
> external recipient (som...@external.com) to the postmaster's address.
>
> Can I do something like this with Sendmail? I have to install any add-ons
> to accomplish this?

Sendmail by its self (sans milters) does not support running any
"""rule(s)""" per say. However, if you know some Perl, I think
MIMEDefang (milter) would be a very good place too start looking as it
has the most flexibility for what you are wanting to do.

Grant. . . .

[Andrew]

"Grant Taylor" <gta...@riverviewtech.net> wrote in message
news:mailman.251.1172024196....@maillists.riverviewtech.net...

Thanks you Grant, it looks like a great product for managing e-mail traffic!
Unfortunately I am not very skilled on Perl scripting, but I'll investigate
about the possibility to use it as soon as I have the time.
In the meanwhile... do you know something more simple to implement and
manage? :)

Andrew

[Grant Taylor]

Andrew wrote:
> Thanks you Grant, it looks like a great product for managing e-mail
> traffic! Unfortunately I am not very skilled on Perl scripting, but
> I'll investigate about the possibility to use it as soon as I have the
> time.

You are welcome. You may wish to talk with David F. Skoll (check the
archives) as he is VERY active with MIMEDefang.

> In the meanwhile... do you know something more simple to implement and
> manage? :)

Look for ideas in line below.

>> For example, I would accept messages sent to a specific internal e-mail
>> address (public...@internal.com) only if the sender address belongs
>> in a specific domain (*@news.external.com).

You may want to look at some of the options for "protected" email
addresses. The idea has usually been presented as a list of special
recipient addresses that can only be sent to if the sending address /
domain is included in a list. I.e. these recipients are only allowed to
receive email from internal senders. Search the news group archive for
(frequent) discussions of such.

>> Another example: I would send a copy of any message sent to a specific
>> external recipient (som...@external.com) to the postmaster's address.

This one is a bit more difficult to implement. Most of the options to
add a recipient are all or nothing, not selective like it sounds like
you are wanting. One option would be to globally add a recipient with
something like Milter-BCC and then have that recipients mail box filter
out and delete things that you do not want to keep.

Grant. . . .

[Andrew]

"Grant Taylor" <gta...@riverviewtech.net> wrote in message

news:mailman.254.1172072694....@maillists.riverviewtech.net...

> Andrew wrote:
>>> For example, I would accept messages sent to a specific internal e-mail
>>> address (public...@internal.com) only if the sender address belongs
>>> in a specific domain (*@news.external.com).
>
> You may want to look at some of the options for "protected" email
> addresses. The idea has usually been presented as a list of special
> recipient addresses that can only be sent to if the sending address /
> domain is included in a list. I.e. these recipients are only allowed to
> receive email from internal senders. Search the news group archive for
> (frequent) discussions of such.
>

I've found a tiny milter plugin which makes me able to reject messages by
using regular expressions: http://www.benzedrine.cx/milter-regex.html. I've
just tried it on FreeBSD. It seems quite simple to manage, and it can
satisfy all our "blocking requirements"... :)

>>> Another example: I would send a copy of any message sent to a specific
>>> external recipient (som...@external.com) to the postmaster's address.
>
> This one is a bit more difficult to implement. Most of the options to add
> a recipient are all or nothing, not selective like it sounds like you are
> wanting. One option would be to globally add a recipient with something
> like Milter-BCC and then have that recipients mail box filter out and
> delete things that you do not want to keep.
>

Milter-BCC looks like what I was searching for to comply with that type of
requirements.

Thanks you again!

Andrew

[jma...@ttec.com]

On Feb 20, 9:17 pm, Grant Taylor <gtay...@riverviewtech.net> wrote:
> Andrew wrote:
> > For example, I would accept messages sent to a specific internal e-mail

> > address (publicfol...@internal.com) only if the sender address belongs in a
> > specific domain (*...@news.external.com).

>
> > Another example: I would send a copy of any message sent to a specific

> > external recipient (some...@external.com) to the postmaster's address.

>
> > Can I do something like this with Sendmail? I have to install any add-ons
> > to accomplish this?
>
> Sendmail by its self (sans milters) does not support running any
> """rule(s)""" per say. However, if you know some Perl, I think
> MIMEDefang (milter) would be a very good place too start looking as it
> has the most flexibility for what you are wanting to do.
>
> Grant. . . .

Sendmail hallmark feature has always been its "rules"

For some examples look at

http://www.sendmail.org/~ca/email/protected.html
http://www.sendmail.org/~ca/email/restrict.html

http://www.jmaimon.com/sendmail/#rcptauthreq
http://www.jmaimon.com/sendmail/patches/rcptauthsender.txt
http://www.jmaimon.com/sendmail

[Andrew]

<jma...@ttec.com> wrote in message
news:1172109820.9...@s48g2000cws.googlegroups.com...

I definitely have a lot to learn about Sendmail... thank you very much, Joe!
:)
It would be great if I will ever be able to use such features, and I'm going
to study how these rules can be used and managed to meet our everyday
requirements.

In the meanwhile, I'll probably spend some time to make one of many milter
plugins work, especially in order to get as many practice as I can before
going deeper in Sendmail's administration.

Thanks you all for giving me these starting points: I'll go on studying from
here.

Andrew

[jma...@ttec.com]

On Feb 23, 10:29 am, "Andrew" <and...@example.com> wrote:

>
> In the meanwhile, I'll probably spend some time to make one of many milter
> plugins work, especially in order to get as many practice as I can before
> going deeper in Sendmail's administration.
>

A list of milters

http://www.jmaimon.com/sendmail/milters

> Thanks you all for giving me these starting points: I'll go on studying from
> here.
>

Good sources for documentation

Sendmail cf/README
Sendmail doc/op
The O'Reilly "Bat Book"

> Andrew

[Andrew]

<jma...@ttec.com> wrote in message
news:1172365731....@t69g2000cwt.googlegroups.com...

Ok, thanks you for all!

Andrew