Re: Lenny/exim4: how to set helo for outgoing SMTP

[randall <randall@songshu.org>]

Kilian wrote:
> > another option would be to ask your isp to change the PTR record on that
> > IP to the  HELO exim uses.
> >     
>
> I have a firewall with a public IP and a PTR record for that IP. There
> are several hosts behind the firewall with private IP addresses. 

i have the same, but i have setup one of them to relay the mails for all 
of them, not sure about your setup but this would simplify your problem 
a lot.
> Some of
> them send mails to the internet, so I cannot change the PTR of the
> firewall to one of those hostnames. I need exim to identify itself in
> the HELO sequence as the PTR record for the firewall; RFC 822 states:
>
>   HELLO (HELO)
>
>    This command is used to identify the sender-SMTP to the
>    receiver-SMTP.  The argument field contains the host name of
>    the sender-SMTP.
>
> Now to the receiver SMTP, my host appears as the firewall, so IMHO, it
> must identify itself with the hostname set in the DNS for the firewall.
>   

correct, but note that that it has to identify with the hostname of your 
"reverse" DNS, it took me a while before i understood this concept myself.

> [...]
>   
> > HELO is for identifying the mailserver, not the domain it sends for.
> > there is no reason why the hostname of the mailserver should match the
> > domain names of the mails it sends out
> >     
>
> I agree.
>
>   
> > if both HELO and the PTR record say mail.server.com there is no problem,
> > whatever the domain of the send mail might be.
> >     
>
> Exactly, and herein lies my problem...
>
>   

maybe i mist something, but what does is it precisely use as its 
hostname at this very moment?


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