setting sender host in Exim4

We are using Exim 4 for mail transport from a V.P.N. When it
tries to send mail, it apparently identifies itself by its virtual
name, and many receiving hosts reject it. I've searched the Web
with no luck. How can I tell Exim 4 to identify the sending host
as its real name so that the receiving hosts can confirm its identity?

-:-
The identical is equal to itself, since it is different.

--Franco Spisani
--
Col. G. L. Sicherman
home: colonel@mail.monmouth.com
work: sicherman@att.com
web:

Re: setting sender host in Exim4

colonel@monmouth.com (A man, a plan, a canal--Buffalo) wrote in
news:dpeo59$jrn$1@shell.monmouth.com:

> We are using Exim 4 for mail transport from a V.P.N. When it
> tries to send mail, it apparently identifies itself by its virtual
> name, and many receiving hosts reject it. I've searched the Web
> with no luck.

Did you RTFM? Search for "hostname" in spec.txt, and on the second
match you will stmble on the primary_hostname option, which is what
you want.

- Fred

Re: setting sender host in Exim4

In , fv+abuse@nospam.epitools.com wrote:
>
> Did you RTFM? Search for "hostname" in spec.txt, and on the second
> match you will stmble on the primary_hostname option, which is what
> you want.

Thanks! That is what I want. Unfortunately, setting it and reloading
the configuration appears to do nothing. The receiving host still
complains (with SMTP code 554) that the real address is "suspect."
This seems to implies that Exim4 is ignoring primary_hostname and
continues to identify itself by its DNS name in SMTP.

-:-
"T.V.? Isn't that a kind of terminal without a keyboard?"

"That's right. It's what we call a dumb terminal."

--soc.culture.netherlands (1992)
--
Col. G. L. Sicherman
home: colonel@mail.monmouth.com
work: sicherman@att.com
web:

Re: setting sender host in Exim4

colonel@monmouth.com (The Human Windmill) wrote in
news:dphj5t$5v1$1@shell.monmouth.com:

> In ,
> fv+abuse@nospam.epitools.com wrote:
>>
>> Did you RTFM? Search for "hostname" in spec.txt, and on the
>> second match you will stmble on the primary_hostname option,
>> which is what you want.
>
> Thanks! That is what I want. Unfortunately, setting it and
> reloading the configuration appears to do nothing.

Hm. Well, it works as advertised for me so I'm skeptical.

What do you mean by "reloading the configuration", what exactly
did you do? "/etc/rc.d/init.d/exim restart", "killall -HUP exim",
or something else?

> The
> receiving host still complains (with SMTP code 554) that the
> real address is "suspect." This seems to implies that Exim4 is
> ignoring primary_hostname and continues to identify itself by
> its DNS name in SMTP.

What exactly is the 55x rejection message?

- Fred

Re: setting sender host in Exim4

In , fv+abuse@nospam.epitools.com wrote:
>
> What do you mean by "reloading the configuration", what exactly
> did you do? "/etc/rc.d/init.d/exim restart", "killall -HUP exim",
> or something else?

I ran "/etc/init.d/exim4 reload". That's supposed to get the job done
without bringing down the server.

> What exactly is the 55x rejection message?

It looks like this:

SMTP error from remote mailer after RCPT TO::
host mail.monmouth.com [209.191.58.1]: \
554 5.7.1 Hostname "[...].dia.cust.qwest.net" suspect

The administrator at the rejecting host (Monmouth Internet) said
it can't do a forward lookup on this host name. This makes sense,
since it's the virtual name that's public. He doesn't seem to mind
my making these experiments.

-:-
One measures a circle, beginning anywhere.

--Charles Fort
--
Col. G. L. Sicherman
home: colonel@mail.monmouth.com
work: sicherman@att.com
web:

Re: setting sender host in Exim4

colonel@mail.monmouth.com (He Comes As No Surprise) wrote in
news:dpmp4v$jr1$1@shell.monmouth.com:

> In ,
> fv+abuse@nospam.epitools.com wrote:
>>
>> What do you mean by "reloading the configuration", what exactly
>> did you do? "/etc/rc.d/init.d/exim restart", "killall -HUP
>> exim", or something else?
>
> I ran "/etc/init.d/exim4 reload". That's supposed to get the
> job done without bringing down the server.

Ah Debian? OK, I believe it.

>> What exactly is the 55x rejection message?
>
> It looks like this:
>
> SMTP error from remote mailer after RCPT
> TO:: host mail.monmouth.com
> [209.191.58.1]: \ 554 5.7.1 Hostname
> "[...].dia.cust.qwest.net" suspect
>
> The administrator at the rejecting host (Monmouth Internet) said
> it can't do a forward lookup on this host name. This makes
> sense, since it's the virtual name that's public. He doesn't
> seem to mind my making these experiments.

Hmm. Well, the error message doesn't tell you explicitly that the
name came from your EHLO. A tcpdump or ethereal packet trace of
the session would answer that question.

And in spite of the counter-productive obfuscation, it looks
suspiciously like a generic PTR name for a dynamic IP.

It's difficult to troubleshoot without any specifics, but it's my
guess that mail.monmouth.com is doing a PTR lookup of the source
IP address it sees your connection coming from, and not liking the
name it gets (either because it doesn't own an A record as he
said, or because it matches a dynamic-detecting regex).

In the OP, you mentioned a VPN. Maybe the SMTP traffic is not
getting routed as you think it is? IOW, you think it traverses
the VPN but it doesn't, or vice-versa.

- Fred