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From: Andreas Meile on 3 Jul 2008 03:28
Dear Sendmail users

In some specific cases, I get postmaster bounce mails like this one:

.... while talking to mailin.example.net.:
>>> RCPT To:carol(a)example.net
<<< 550-5.7.1 {mx015} The recipient does not accept mails from 'example.org'
over foreign mailservers.
<<< 550-5.7.1 According to the domain's SPF record your host '192.0.2.47' is
not a designated sender.
<<< 550 5.7.1 ( http://portal.example.net/serverrules )
550 5.1.1 carol(a)example.net... User unknown

Situation: I'm maintaining Bob's MTA server where there is a forwarding rule

bob(a)example.com carol(a)example.net

in /etc/mail/virtusertable.

Carol's MTA strongly checks SPF as a antispam and mail forgery
countermeasure and does not allow SMTP whitelisting.

Alice's ISP has defined an SPF record like this one:

pingu:~> nslookup -q=txt example.org
Server: dns1.example.com
Address: 192.0.2.46

example.org text = "v=spf1 a:mailout.example.org -all"

As I can understand, my MTA does not change the envelope address, i.e. uses
"MAIL FROM: alice(a)example.org" instead "MAIL FROM: bob(a)example.com" in the
SMTP dialogue, so my host appears as a foreign host for Carol's receiving
MTA.

I already found the following links about this topic:

http://www.openspf.org/FAQ/Forwarding
http://en.wikipedia.org/wiki/Sender_Rewriting_Scheme

Question: Is there probably a suitable configuration directive on Sendmail's
..mc configuration level or do I have to use a utility like procmail for each
mail forwarding to an external target (theoretically for those only which
actively checks SPF on the income side) as shown in openspf.org's examples?

Thanks in advance. :-)

Andreas
--
Teste die PC-Sicherheit mit www.sec-check.net



From: D. Stussy on 3 Jul 2008 16:00
"Andreas Meile" <usenet(a)andreas-meile.ch> wrote in message
news:6d3ddoFkk35U1(a)mid.individual.net...
> In some specific cases, I get postmaster bounce mails like this one:
>
> ... while talking to mailin.example.net.:
> >>> RCPT To:carol(a)example.net
> <<< 550-5.7.1 {mx015} The recipient does not accept mails from
'example.org'
> over foreign mailservers.
> <<< 550-5.7.1 According to the domain's SPF record your host '192.0.2.47'
is
> not a designated sender.
> <<< 550 5.7.1 ( http://portal.example.net/serverrules )
> 550 5.1.1 carol(a)example.net... User unknown
>
> Situation: I'm maintaining Bob's MTA server where there is a forwarding
rule
>
> bob(a)example.com carol(a)example.net
>
> in /etc/mail/virtusertable.
>
> Carol's MTA strongly checks SPF as a antispam and mail forgery
> countermeasure and does not allow SMTP whitelisting.
>
> Alice's ISP has defined an SPF record like this one:
>
> pingu:~> nslookup -q=txt example.org
> Server: dns1.example.com
> Address: 192.0.2.46
>
> example.org text = "v=spf1 a:mailout.example.org -all"
>
> As I can understand, my MTA does not change the envelope address, i.e.
uses
> "MAIL FROM: alice(a)example.org" instead "MAIL FROM: bob(a)example.com" in the
> SMTP dialogue, so my host appears as a foreign host for Carol's receiving
> MTA.
>
> I already found the following links about this topic:
>
> http://www.openspf.org/FAQ/Forwarding
> http://en.wikipedia.org/wiki/Sender_Rewriting_Scheme
>
> Question: Is there probably a suitable configuration directive on
Sendmail's
> .mc configuration level or do I have to use a utility like procmail for
each
> mail forwarding to an external target (theoretically for those only which
> actively checks SPF on the income side) as shown in openspf.org's
examples?
>
> Thanks in advance. :-)
>
> Andreas

Supposedly "milter-srs". I don't use it.


From: Grant Taylor on 3 Jul 2008 23:02
On 7/3/2008 2:28 AM, Andreas Meile wrote:
> Question: Is there probably a suitable configuration directive on
> Sendmail's .mc configuration level or do I have to use a utility like
> procmail for each mail forwarding to an external target
> (theoretically for those only which actively checks SPF on the income
> side) as shown in openspf.org's examples?

Ah, don't you love it when something works like it is intended to?

Seriously, there is not any good way to get Sendmail out of the box to
do Sender Rewriting Scheme. However with a little help Sendmail can be
made to do it.

Take a look at SRS-socketmap (http://www.srs-socketmap.info/) for
information at creating a new map to convert the envelope sender address
for you.

I've been using this SRS socketmap (or at least a *very* close config)
for the last year and half with very little trouble. Well, almost. I
had to create a new mailer that did not use SRS because I ran in to some
receiving servers that balked at receiving an SRS envelope sender.

I have created a custom srs.m4 file for inclusion in to the sendmail.mc
file that includes a new mailer that can be used via MailerTable to work
with domains that do not play well with SRS. If you would like a copy
of my srs.m4 feature file, let me know and I'll email it to you.



Grant. . . .

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