> On Thu, 21 Dec 2000 jasonr@??? wrote:
>
> > Is it at all possible to disable *all* rdns lookups for smtp sending?
>
> Do you really mean sending? I don't think Exim ever does reverse lookups
> while sending.
Yes, you are correct, that was bad wording on my part :)
> Or perhaps you mean when something else is sending TO Exim?
>
> Exim only looks up a host name if
>
> (a) You tell it to, by setting host_lookup.
This is commented out, though i have tried various settings at one time or another.
> (b) It needs the name because you have specified some checking by name,
> e.g. something like
>
> host_accept_relay = *.some.domain
this line currently reads:
host_accept_relay = 127.0.0.1:mysql;MYSQL_RELAY:
with MYSQL_RELAY:
MYSQL_RELAY = SELECT ip FROM relay_ip WHERE ip="${sender_host_address}" AND DATE_SUB(NOW(), INTERVAL RELAY_TIMEOUT) < ts
> (c) The client host is broken, and sends a HELO command like
>
> HELO the.server.domain.name
>
> What it is supposed to send is
>
> HELO the.client.domain.name
I dont know what is the case here, I am using netscape messenger 4.7something for linux.
I do know that we are behind a firewall, and that there is no rdns for the firewall machine.
> In this case Exim does a lookup to get a client name. Otherwise the
> entries in the log get very confusing.
>
> You can test why Exim is doing a lookup by running a simulated SMTP
> session using the -bh option, e.g. exim -bh 1.2.3.4 This should
> enable you to find out why it is doing lookups.
Here is a sample session:
exim -bh 198.107.66.125
**** SMTP testing session as if from host 198.107.66.125
**** Not for real!
>>> host in host_lookup? no (option unset)
>>> host in host_reject? no (option unset)
>>> host in host_reject_recipients? no (option unset)
>>> host in sender_unqualified_hosts? no (option unset)
>>> host in receiver_unqualified_hosts? no (option unset)
>>> host in helo_verify? no (option unset)
>>> host in helo_accept_junk_hosts? no (option unset)
220 metro ESMTP Exim 3.20 #8 Tue, 26 Dec 2000 09:14:15 -0800
helo firewall.argia.net
>>> firewall.argia.net in local_domains? no (end of list)
250 metro Hello firewall.argia.net [198.107.66.125]
mail from:<test@???>
>>> test@??? in sender_reject? no (option unset)
>>> test@??? in sender_reject_recipients? no (option unset)
250 <test@???> is syntactically correct
rcpt to:<test@???>
>>> test.com in local_domains? no (end of list)
>>> test.com in relay_domains? no (end of list)
>>> looking up host name for 198.107.66.125
>>> IP address lookup failed
>>> host in host_accept_relay? no (failed to find host name or lookup deferred)
550 relaying to <test@???> prohibited by administrator (failed to find host name from IP address)
LOG: refused relay (host) to <test@???> from <test@???> H=(firewall.argia.net) [198.107.66.125] (failed to find host name from IP address)
quit
221 metro closing connection
for some reason it is still trying to do dns lookups, tho i have to the best of my knowledge told it not to...
> --
> Philip Hazel University of Cambridge Computing Service,
> ph10@??? Cambridge, England. Phone: +44 1223 334714.
