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Old 02-18-2007, 10:31 PM   #1
sbaker25
LQ Newbie
 
Registered: Feb 2007
Posts: 1

Rep: Reputation: 0
RBL blocking based on DHCP address even with SMART_HOST (sendmail)


I have a mail delivery problem in that my mail is bouncing due to rules in the RBL - spamhaus PBL to be specific because my local address is in a known DHCP block. I think it is important to note that everything WAS working fine, so I don't know if I moved from an unrecognized DHCP address into a recognized block (on the same ISP), or if the recipient changed their use of the RBL.

I specifically got insight into the problem when I noticed that I was never receiving mail that I forward to my work account and my IT administrator looked into it.

I was surprised to learn that, despite the fact that I am sending mail using a configuered SMART_HOST (my connection is authenticated, but I don't think that makes any difference), my mail was being bounced based on the IP address of my local sendmail.

Does anyone have any idea how I would get around this? I don't want to connect directly to the remote sendmail, especially with pine, because I need to use SMTP AUTH to work with it.

My mail headers look like this:

Code:
Received: from my.smarthost.com (my.smarthost.com [a.b.c.d])
        by destination.domain.com (Postfix) with ESMTP id 9A20E676B6
        for <recipient@destination.domain.com>; Sun, 18 Feb 2007 20:52:24 -0500 (EST)
Received: from my.local.machine (a.b.c.d.my.dhcp.domain [a.b.c.d])
        (authenticated bits=0)
        by my.smarthost.com (8.13.6.20060614/8.13.6) with ESMTP id l1J1qNtG
090525
        for <recipient@destination.domain.com>; Sun, 18 Feb 2007 20:52:23 -0500 (EST)
Received: from my.local.machine (my.local.machine [127.0.0.1])
        by my.local.machine (8.12.8/8.12.8) with ESMTP id l1J1qIhd020194
        for <recipient@destination.domain.com>; Sun, 18 Feb 2007 20:52:18 -0500
Received: from localhost (me@localhost)
        by my.local.machine (8.12.8/8.12.8/Submit) with ESMTP id l1J1qHW702019
0
        for <recipient@destination.domain.com>; Sun, 18 Feb 2007 20:52:18 -0500
Date: Sun, 18 Feb 2007 20:52:17 -0500 (EST)
So, the mail IS being relayed through the SMART_HOST, but the RBL is still considering the original source address in the header as valid reason to reject me.

Here is my sendmail.mc with all the comment lines omitted:

Code:
divert(-1)dnl
include(`/usr/share/sendmail-cf/m4/cf.m4')dnl
VERSIONID(`setup for Red Hat Linux')dnl
OSTYPE(`linux')dnl
define(`SMART_HOST',`[my.smarthost.com]')
define(`confDEF_USER_ID',``8:12'')dnl
define(`confTRUSTED_USER', `smmsp')dnl
define(`confTO_CONNECT', `1m')dnl
define(`confTRY_NULL_MX_LIST',true)dnl
define(`confDONT_PROBE_INTERFACES',true)dnl
define(`PROCMAIL_MAILER_PATH',`/usr/bin/procmail')dnl
define(`ALIAS_FILE', `/etc/aliases')dnl
define(`UUCP_MAILER_MAX', `2000000')dnl
define(`confUSERDB_SPEC', `/etc/mail/userdb.db')dnl
define(`confPRIVACY_FLAGS', `authwarnings,novrfy,noexpn,restrictqrun')dnl
define(`confAUTH_OPTIONS', `A')dnl
TRUST_AUTH_MECH(`EXTERNAL DIGEST-MD5 CRAM-MD5 LOGIN PLAIN')dnl
define(`confAUTH_MECHANISMS', `EXTERNAL GSSAPI DIGEST-MD5 CRAM-MD5 LOGIN PLAIN')
define(`confTO_IDENT', `0')dnl
FEATURE(`no_default_msa',`dnl')dnl
FEATURE(`smrsh',`/usr/sbin/smrsh')dnl
FEATURE(`mailertable',`hash -o /etc/mail/mailertable.db')dnl
FEATURE(`virtusertable',`hash -o /etc/mail/virtusertable.db')dnl
FEATURE(redirect)dnl
FEATURE(always_add_domain)dnl
FEATURE(use_cw_file)dnl
FEATURE(use_ct_file)dnl
FEATURE(local_procmail,`',`procmail -t -Y -a $h -d $u')dnl
FEATURE(`access_db',`hash -T<TMPF> -o /etc/mail/access.db')dnl
FEATURE(`blacklist_recipients')dnl
FEATURE(`authinfo',`hash /etc/mail/authinfo.db')dnl
EXPOSED_USER(`root')dnl
DAEMON_OPTIONS(`Port=smtp,Addr=127.0.0.1, Name=MTA')dnl
FEATURE(`accept_unresolvable_domains')dnl
LOCAL_DOMAIN(`localhost.localdomain')dnl
MAILER(smtp)dnl
MAILER(procmail)dnl
Any ideas or insights would be welcome.

Thanks for reading,
Shane
 
  


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