Actually, if he's doing this in a filter, that really doesnt apply,
becuase exim will have already accepted the message.
If he wants to sort or /dev/null the message after its been recieved if
the helo doesnt match the rDNS, thats entirely up to him.
Now, sinces there are literly TONS of legitimate mail servers out there
that dont get this right (in several different ways), he may be cutting
of the nose to spite the face, but I dont beleive any RFC forbids that
;)
On Mon, 17 Sep 2001, Matthew Byng-Maddick wrote:
> On Mon, Sep 17, 2001 at 04:40:06PM +0100, Alan Thew wrote:
> > The following type of thing happens all the time
> > Received: from 209-187-167-231.hsacorp.net ([209.187.167.231]
> > helo=hotmail.com)
> > I would like to compare the actual rDNS data with the HELO info in the
> > specific case of hotmail.
>
> RFC1123:
> | 5.2.5 HELO Command: RFC-821 Section 3.5
> |
> | The sender-SMTP MUST ensure that the <domain> parameter in a
> | HELO command is a valid principal host domain name for the
> | client host. As a result, the receiver-SMTP will not have to
> | perform MX resolution on this name in order to validate the
> | HELO parameter.
> |
> | The HELO receiver MAY verify that the HELO parameter really
> | corresponds to the IP address of the sender. However, the
> | receiver MUST NOT refuse to accept a message, even if the
> | sender's HELO command fails verification.
>
> MBM
>
>
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