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postfix and dns configuration

I've been having problems the last week with setting up postfix to be able to send mail without it being flagged as spam or completely rejected by other mail servers. I believe it mainly involves with my DNS settings and how I have my hostname set up. Here are my configuration files:

main.cf

Code:

broken_sasl_auth_clients = yes

command_directory = /usr/sbin

config_directory = /etc/postfix

daemon_directory = /usr/lib/postfix

debug_peer_level = 2

default_destination_concurrency_limit = 20

home_mailbox = .maildir/

html_directory = /usr/share/doc/postfix-2.2.10/html

inet_interfaces = all

local_destination_concurrency_limit = 2

local_recipient_maps = 

mail_owner = postfix

mailbox_size_limit = 102400000

mailq_path = /usr/bin/mailq

manpage_directory = /usr/share/man

message_size_limit = 20480000

mydestination = 

mydomain = mydomain.com

myhostname = MyBox.mydomain.com

mynetworks = xxx.xxx.193.0/24, 127.0.0.0/8, xxx.xxx.249.105, xxx.xxx.208.103

mynetworks_style = subnet

newaliases_path = /usr/bin/newaliases

queue_directory = /var/spool/postfix

readme_directory = /usr/share/doc/postfix-2.2.10/readme

sample_directory = /etc/postfix

sendmail_path = /usr/sbin/sendmail

setgid_group = postdrop

smtp_tls_note_starttls_offer = yes

smtp_use_tls = yes

smtpd_recipient_restrictions = permit_sasl_authenticated,      permit_mynetworks,      reject_unauth_destination,      check_policy_service unix:private/policy-spf        permit

smtpd_sasl_auth_enable = yes

smtpd_sasl_local_domain = 

smtpd_sasl_security_options = noanonymous

smtpd_tls_CAfile = /etc/postfix/cacert.pem

smtpd_tls_auth_only = yes

smtpd_tls_cert_file = /etc/postfix/newcert.pem

smtpd_tls_key_file = /etc/postfix/newreq.pem

smtpd_tls_loglevel = 3

smtpd_tls_received_header = yes

smtpd_tls_session_cache_timeout = 3600s

smtpd_use_tls = yes

tls_random_source = dev:/dev/urandom

unknown_local_recipient_reject_code = 550

virtual_alias_maps = mysql:/etc/postfix/mysql_virtual_alias_maps.cf

virtual_gid_maps = static:207

virtual_mailbox_base = /var/vmail

virtual_mailbox_domains = mysql:/etc/postfix/mysql_virtual_domains_maps.cf

virtual_mailbox_limit = 51200000

virtual_mailbox_maps = mysql:/etc/postfix/mysql_virtual_mailbox_maps.cf

virtual_minimum_uid = 207

virtual_transport = virtual

virtual_uid_maps = static:207

DNS Zone:

Code:

$TTL 86400

mydomain.com.    IN      SOA    ns1.mydomain.com. root.mydomain.com. (

                        2006070816

                        21600

                        3600

                        1209600

                        3600 )



                TXT    "My Domain"



mydomain.com.    IN      NS      ns1.mydomain.com.        ; Hostname of nameserver

mydomain.com.    IN      NS      ns2.mydomain.com.        ; Slave nameserver



mydomain.com.    IN      TXT    "v=spfl a mx ptr -all"  ; SPF record



@              IN      A      xxx.xxx.193.34

ns1            IN      A      xxx.xxx.193.34 ; Nameserver 1

ns2            IN      A      xxx.xxx.193.35 ; Nameserver 2

mail            IN      A      xxx.xxx.193.34

Mybox          IN      A      xxx.xxx.193.34

www            IN      CNAME  @; IP of webserver



mydomain.com.  IN      MX      10 MyBox.mydomain.com.

Reverse Zone:

Code:

This is handled by my colo provider. This is what dnsstuff.com returns for my reverse zone.

34.193.xxx.xxx.in-addr.arpa mydomain.com [TTL=21600]

Hostname:

Code:

# hostname --short

MyBox

# hostname --fqdn

MyBox.mydomain.com

EHLO:

Code:

# telnet localhost 25

Trying 127.0.0.1...

Connected to localhost.

Escape character is '^]'.

220 MyBox.mydomain.com ESMTP Postfix

EHLO mydomain.com (replace with virtual domains as well and returns the below for all)

250-MyBox.mydomain.com

250-PIPELINING

250-SIZE 20480000

250-VRFY

250-ETRN

250-STARTTLS

250 8BITMIME

quit

221 Bye

Connection closed by foreign host.

Other notes. I am running on Gentoo and I am using postfixadmin with mysql. I also have 3 virtual domains I am managing and I would like to send email from them as well. I have their forward zones done the same as my main domain as above, but for the MX records I use mail.virtual-domain-x.com which points to xxx.xxx.193.34.

This problem has just been fustrating me for the past week and I've tried various things from google searches and the gentoo forums with no avail. It would be great if I can get to the point that my mail no longer gets flagged as spam by providers such as gmail.

My question would be: Are you using a DHCP address with your broadband account with your ISP? This would be one reason you're being flagged as a spammer. Most ISP's and major mail servers with accounts like Yahoo, MSN and Gmail all reject mail servers that have DHCP connections as they are most likely an open relay for spammers.

The server is a colo box housed in a datacenter, so no I'm not using a DHCP address.

Quote:

Originally Posted by Soynuts

The server is a colo box housed in a datacenter, so no I'm not using a DHCP address.

Check and make sure the IP you're using isn't on any existing spamhaus or spam lists. One site I know of is doing a search on http://whois.sc and look under Blacklist Status: in the results to see if it's clear or not.

Other lists are http://www.spamhaus.org/ and http://www.spamcop.com/ to name just a few.

Also if you can provide a few headers of returned mail, that might give some insight of the problem.

Just checked those out, I'm not on any of those lists. Here is a header from a message in gmail that ends up flagged as spam. This message was sent with the php mail() method from the webserver on the same box.

Code:

Delivered-To: myGmailAccount@gmail.com

Received: by 10.90.66.3 with SMTP id o3cs579455aga;

        Sun, 10 Dec 2006 13:14:31 -0800 (PST)

Received: by 10.64.241.3 with SMTP id o3mr9618223qbh.1165785271604;

        Sun, 10 Dec 2006 13:14:31 -0800 (PST)

Return-Path: <apache@mydomain.com>

Received: from MyBox.mydomain.com (mydomain.com [xxx.xxx.193.34])

        by mx.google.com with ESMTP id f17si5673723qba.2006.12.10.13.14.31;

        Sun, 10 Dec 2006 13:14:31 -0800 (PST)

Received-SPF: pass (google.com: best guess record for domain of apache@mydomain.com designates xxx.xxx.193.34 as permitted sender)

Received: by MyBox.mydomain.com (Postfix, from userid 81)

        id 28CB2E7C243; Sun, 10 Dec 2006 16:17:49 -0600 (CST)

To: myGmailAccount@gmail.com

Subject: Test

MIME-Version: 1.0

Content-type: text/html; charset=utf-8 

From: User1 <user1@virtual-domain1.com>

Message-Id: <20061210221749.28CB2E7C243@MyBox.mydomain.com>

Date: Sun, 10 Dec 2006 16:17:49 -0600 (CST)

If you need me to post my real domain (and virtual domains) I will post it.

Does any other service flag it? I'm sure with gmail you can flag a message as not being spam. Perhaps they've never seen this domain so that's why it's being flagged for some reason.

I got some friends to help out with it with their email addresses. All the gmail and hotmail people got it as spam. Yahoo did not flag it as spam. I don't have any "non-major" email accounts I can try it with.

Quote:

Originally Posted by Soynuts

If it Yahoo didn't flag it, most likely it's just settings on each ISP or email provider. Try sending an email to possibly some recipients that aren't a major provider that run their mail server for a business and see if their spam solutions if they have any block or flag it.

Mail servers do perform reverse lookups to revalidate a sending MTA's domain or FQDN and it rejects those that
doesn't resolve properly.

If it doesn't resolve, this is what will be shown.

@webmaster:~$ host your.internet.ip.add
Host your.internet.ip.add.in-addr.arpa not found: 3(NXDOMAIN)

This one next is what should be expected.

@webmaster:~$ host your.internet.ip.add
your.internet.ip.add.in-addr.arpa domain name pointer your.domain.com.

----------
GANI

My DNS does resolve correctly when I use dnsstuff.com.

I was able to test it with a non major public email provider. I sent a test email to my work email, which has pretty tight spam protection and it arrived in my mail box just fine. So it seems that gmail and hotmail are the problems and not my smtp server. I would assume talking with hotmail/gmail would be the only way to get this resolved... if that's even possible.

On thing is that your envelope sender does not match the body sender. The routing information (rfc2821) is for apache@mydomain.com, but your body sender (rfc2822) is user1@virtual-domain1.com. Some anti-spam techniques compare the envelope information with that in the body and give it a higher spam score if the addresses do not match.

I've tried it with both matching (apache@mydomain.com for the envelope and body) and it still ends up getting flagged as spam. I've run out of ideas I could try. Gmail and hotmail are the only ones I'm finding to have issues, no other mail server seems to flag it. I have no idea what other techniques hotmail and gmail could be using that other mail servers are not, such as yahoo. The SPF entry was newest addition which I added a week ago to my DNS zone.