Is this normal

Hi.

My provider has an IP spoofing protection enabled. This makes mail
relaying impossible. I explain ...

I am "user1@ere.com". I have another e-mail address ("user2@tobi.com"),
which I forward to "user1@ere.com".

user2@tobi.com -> user1@ere.com

Now ... when a user from *@ere.com writes to user2@tobi.com, the mail
gets forwarded to user1@ere.com. The "ere.com" server sees that the
FROM: is "ere.com", but the IP where the mail is coming from is from
"tobi.com", and rejects the mail as spoofing!

Here the message:

---- cut here ----
This is the Postfix program at host willum.dreamhost.com.

I'm sorry to have to inform you that the message returned
below could not be delivered to one or more destinations.

For further assistance, please send mail to <postmaster>

If you do so, please include this problem report. You can
delete your own text from the message returned below.

The Postfix program

<user1@ere.com>: said: 500 5.1.7 Spoofing denied
---- cut here ----

Is this the normal configuration of postfix ???

--
Georges

Dnia Fri, 23 Jul 2004 09:39:38 +0200
Georges <void@void.com> Napisal:

> Hi.
>
> My provider has an IP spoofing protection enabled. This makes mail
> relaying impossible. I explain ...
>
> I am "user1@ere.com". I have another e-mail address ("user2@tobi.com"),
> which I forward to "user1@ere.com".
>
> user2@tobi.com -> user1@ere.com
>
> Is this the normal configuration of postfix ???

No, you need some external filter. Like rmxf or other used probably as
policy_delegation. Which checks for some kind of spf records or even A or
MX addresses.
This filters are real virus/spam killers. The only way some self sending
worm can hit You (with A or MX checks on) is by sending him first for
some list, where you are subscribed, or for forwarded mail. It is great
help when there are new viruses in town, and anty-vir signatures do not
match them yet.

But, Your question is probably like: how to forward with such mechanism
turned on.
If You can use something that rewrites envelope sender on tobi.com then it
should work. One choice is procmail.

pozdr.
Janek

--
24 godziny w dobie, 24 piwa w skrzynce. Przypadek? Nie wydaje mi siê...
S.Wright

Jan Alboszta wrote:

> But, Your question is probably like: how to forward with such mechanism
> turned on.
> If You can use something that rewrites envelope sender on tobi.com then it
> should work. One choice is procmail.

Thanks for the info.

No, I have nothing to rewrite the envolope since I have no direct access
to the system of tobi.com.

I guess I have to live with the restriction ;((

--
Georges