Postfix - antispam and relay package

yaboc

Sorry, yaboc, Bismarck is second. You'll have to go third :)

If Google is your main problem and you missed this post, give it a try.

It is a bit of a "broad brush" but it's been working well for me.

ha as long as it gets implemented i can wait ;) thanks for the google list biggsy, but there are other emails that we get from same domain / multiple MTAs and it's annoying. sometimes it can take hours for the mail to finally come through.

also i noticed 'permit' is used per line whereas the HINT says to use OK / REJECT
i put OK and see if it works for google servers.

Thanks

Bismarck

@biggsy:

Sorry, yaboc, Bismarck is second. You'll have to go third :)

If Google is your main problem and you missed this post, give it a try.

It is a bit of a "broad brush" but it's been working well for me.

Thanks biggsy, but unfortunately google is not the only problem, I'm tweaking my whitelist (yahoo, hotmail etc…) since few days but its a demanding job over time, so postscreen_dnsbl_whitelist_threshold would be a great help here.

jaredadams

Hi, I'm looking for some clarification on settings. Currently I have a good amount of legit email bouncing off the Helo tests

Jun 24 09:16:51 pfsense postfix/smtpd[47197]: NOQUEUE: reject: RCPT from outbound1.notrealdomain.com[12.xx.xxx.82]: 550 5.7.1 <ironport1.notrealdomain.com>: Helo command rejected: Host not found</ironport1.notrealdomain.com>

I think our problem is the mismatch in hostnames. I dont want to turn off the helo tests completely as they serve a good function for when no helo at all is recieved back, but I'd like to be able to ignore these mismatches.

Bismarck

@jaredadams:

Hi, I'm looking for some clarification on settings. Currently I have a good amount of legit email bouncing off the Helo tests
Jun 24 09:16:51 pfsense postfix/smtpd[47197]: NOQUEUE: reject: RCPT from outbound1.notrealdomain.com[12.xx.xxx.82]: 550 5.7.1 <ironport1.notrealdomain.com>: Helo command rejected: Host not found</ironport1.notrealdomain.com>
I think our problem is the mismatch in hostnames. I dont want to turn off the helo tests completely as they serve a good function for when no helo at all is recieved back, but I'd like to be able to ignore these mismatches.

https://forum.pfsense.org/index.php?topic=63343.0

Try in helo acl field:

/ironport1.notrealdomain.com/ OK (this is for HELO)

and in CIDR field:

12.xx.xxx.82 OK (this is for legitimate clients without or wrong rDNS)

gnordli

I am using the postfix forwarder on pfsense.

Outbound email sent to google is getting tagged as spam and ending up in people's spam folder.

I have done some testing using http://www.allaboutspam.com/email-server-test/ and it passes everything except for BATV and DKIM.

From what I have read the lack of DKIM can cause google to mark it as spam.

Any ideas on setting DKIM up on pfsense?

thanks,

Geoff

toddh

Hello,

I am new to pfSense and am looking at using it to replace some postfix - spamassassin - clam gateways. We have a mail server behind and we want to forward several domains.

For the Recipients we are exporting the user list to Postfix via clean text url and that is working perfectly.

Does anyone have a way to automate/read the Forwarding Domains rather than enter them manually?

In our current system we export the transport file to the gateways. The transport file is used for both the transport_map and the relay_domains. I started working on this then realizes someone else probably has come across the same issue.

Thanks!

Todd

yaboc

Hi,

I've been using postfix forwarder for about a year now which listens on loopback and delivers mail to internal exchange. However i can't telnet either the main WAN on 25 that postfix forwarder listens on on exchange (on it's own separate IP).

We must allow one host to be able to relay the mail. How would i set this up ?

Also not sure if this will make things easier or more complicated but we have the ability to connect with the host with IPSEC and relay directly to exchange however I can't telnet to exchange even via the IPSEC via the local exchange IP.

Would postfix forwarder have any say in it as well ? Catching mail on 25 that goes through VPN? Anything i have to set up to get this working?

Thanks

yaboc

biggsy

Toddh,

The list of relay domains and their corresponding destination IPs is held in /usr/pbi/postfix-amd64/etc/postfix/transport

I think this is just used to build /usr/pbi/postfix-amd64/etc/postfix/transport**.db** using the command

postmap  /usr/pbi/postfix-amd64/etc/postfix/transport

The transport.db file is then used by postfix, rather the plaintext transport file.

You could try creating a new transport file in the right format and run the above command but I suspect both would be overwritten if postfix is restarted.

biggsy

Yaboc,

Are you saying that you want an external host to go directly to your Exchange server, bypassing postfix?

If so, would it not be easier to create a rule on your WAN, above the postfix one, to pass port 25 from that source host to the Exchange server?

yaboc

biggsy,

that is correct, i have one host that i'd like to relay email through our exchange bypassing postfix, because it doesn't seem to work (relaying) with the default postfix forwarder setup.

i'd prefer to make it as secure as possible and have ipsec in place between the host and our exchange but i can't even telnet to exchange using local ip, which is strange because i can do it from through other tunnels i have set up and the rules are any/any among tunnels.

i'll try your suggestion and report back but preferably i'd like to get it to work over ipsec if possible.

thank you!

twaldorf

Is it possible to have StartTLS with PFS on pfSense 2.1.5-RELEASE (i386) / FreeBSD 8.3-RELEASE-p16 with Postfix 2.10.2 pkg v.2.3.7?

If it's possible: What do I have to add to custom main.cf options and with which options I have to create a working self signed certificate/key?

pyrodex

Any chance of getting this to work in 2.2?

FlashPan

Hi all,

Hoping someone can help me out with this type of spam I just cannot figure out how to stop.

Below is the message header for they type of emails I am getting

In outlook I see and email from Louie.Whaley@bt.com but obviously we can see it's not come from there but bondhub.

Is it possible to stop this "type" of email without having to manually enter each domain to be blocked/stopped?

Apologies if this is a rather vague question with little info on my setup as I am not sure what is pertinent to you chaps of what you require and I am the more click, install and depend on gui type to setup this type of stuff.

What I can say is that I am running:

pfsense 2.1.5 32 bit
postfix 2.10.2 pkg v.2.3.7
mailscanner 4.84.6 v.0.2.6

I do have other apps like pfblocker and snort running but would prefer to use mailscanner if possible to block this type of stuff.

Thanks in advance for any replies. It is most appreciated.

Received: from mail.XXXX.co.uk (192.168.XXX.XXX) by XXXX.XXXX.corp
(192.168.XXX.XXX) with Microsoft SMTP Server id 14.3.210.2; Fri, 26 Sep 2014
14:07:08 +0100
Received: from 106.247.219.88.rev.sfr.net (106.247.219.88.rev.sfr.net
[88.219.247.106]) by mail.XXXX.co.uk (Postfix) with ESMTP id E93C867BB for
xxxx@xxxx.co.uk; Fri, 26 Sep 2014 14:07:01 +0100 (BST)
Message-ID: ck386wzl.3794015@bondhub.comDate: Fri, 26 Sep 2014 15:13:09 +0100
From: Louie Whaley louie.whaley@bt.comUser-Agent: Mozilla/5.0 (Windows NT 6.1; rv:24.0) Gecko/20100101 Thunderbird/24.2.0
MIME-Version: 1.0
To: xxxx@xxxx.co.ukSubject: Important - BT Digital File
Content-Type: text/plain; charset="ISO-8859-1"; format=flowed
Content-Transfer-Encoding: 7bit
X-sufu-MailScanner-Information: Please contact the ISP for more information
X-sufu-MailScanner-ID: E93C867BB.A2828
X-sufu-MailScanner: Found to be clean
X-sufu-MailScanner-From: onyxnf@bondhub.com
X-Spam-Status: No
Return-Path: onyxnf@bondhub.com
X-MS-Exchange-Organization-AuthSource: XXXX.XXXX.corp
X-MS-Exchange-Organization-AuthAs: Anonymous/xxxx@xxxx.co.uk /louie.whaley@bt.com /ck386wzl.3794015@bondhub.com /xxxx@xxxx.co.uk

Bismarck

@FlashPan:

Hoping someone can help me out with this type of spam I just cannot figure out how to stop.

Hi FlashPan, this can be done easily with postfix:

1. Setup a proper RBL server List, you can combine as many as you wish if you set a higher RBL threshold. Which could block dynamic ips by default also = 106.247.219.88.rev.sfr.net [88.219.247.106])

2. Postfix > antispam > Header add this:

*/^Received:.rev.sfr.net / REJECT #will reject ALL dynamic ips from *rev.sfr.net

/^From:.*@bt.com/ REJECT #will reject all mail from someone@bt.com

/^Subject:.*(Important - BT Digital File):/ REJECT #will reject all mail with subject Important - BT Digital File

4. Subscribe additional rules for MailScanner/Spamassassin (google it)

https://wiki.apache.org/spamassassin/CustomRulesets

5. You also can write your own rules for MailScanner/Spamassassin:

https://wiki.apache.org/spamassassin/WritingRules

place your custom rules in /var/db/spamassassin/3.004000/70_myrules.cf and restart MailScanner. After adding new rules always check your mail log for errors or false positives! But Postfix is easier to handle, so start there.

Using pfblocker for spam prevention is a BAD idea, because you will miss if a legit email gets blocked etc….

Good luck!

biggsy

@FlashPan:

Subject: Important - BT Digital File

Hmmm, smells like phish. Hope your users are clued up about that stuff.

An example of what Bismarck is recommending in point 1.

Paste this into your Postfix > Antispam > RBL Server list

zen.spamhaus.org*2, bl.spamcop.net, 0spam.fusionzero.com

and set your RBL threshold to 2.

spamhaus catches most of this sort of stuff on my system, hence the *2 to breach the threshold.

88.219.247.106 is definitely listed.

biggsy

@pyrodex:

Any chance of getting this to work in 2.2?

Are you talking about Postfix forwarder on 2.2? I have had some problems with that.

Installing postfix on 2.2 (with a config restored from 2.1.5) I'm getting the following:

postfix/postfix-script[56365]: fatal: no Postfix daemon directory /usr/local/libexec/postfix!

and


php-fpm[7873]: /pkg_mgr_install.php: The command '/usr/local/sbin/postfix reload' returned exit code '1', the output was 'cd: /usr/local/libexec/postfix: No such file or directory'
php-fpm[7873]: /pkg_mgr_install.php: The command '/usr/local/sbin/postfix reload' returned exit code '1', the output was 'cd: /usr/local/libexec/postfix: No such file or directory'

Then the following repeats about 5 or 6 times:

php-fpm[8074]: /pkg_edit.php: The command '/usr/local/sbin/postfix reload' returned exit code '1', the output was 'cd: /usr/local/libexec/postfix: No such file or directory'
php-fpm[8074]: /pkg_edit.php: The command '/usr/local/sbin/postfix reload' returned exit code '1', the output was 'cd: /usr/local/libexec/postfix: No such file or directory'

All this could be due to the restored config but I don't know.

FlashPan

Thanks Bismark and biggsy,

I do have zen.spamhaus.org, bl.spamcop.net, dnsbl.sorbs.net set in my RBL list and the threshold is set to 2 already. These options have been set for months. On my firewall I'm set the automatic nat outbound rule generation so none of the rbl servers should be blocked to interogate.

Postfix is set the listen on LAN, WAN and loopback (quite a while back I only had Lan or Wan selected - if I remember correctly I think a version upgrade stop mail flowing through and only using all 3 got it working again).

Access Lists > Header:

/^Subject:/ WARN
/^From:/ HOLD
/^To:.*@MyDomain.co.uk/ HOLD

Antispam > Header verifiction: set to basic as when set to string alot of legit emails do not make it through.

Antispam > After greeting tests: all selected

In the Mailscanner app under AntiSpam > Spamchecks the only element I have selected is "Spam Checks (yes)" Nothing else is selected or have a value entered. Could that be causing some sort of clash?

Mailscanner > AntiSpam > Spam Assassin > Features: All is selected except for Include Binary Attachments and Wait during bayes rebuild

Am still at a loss :)

One other thing I have noticed is that with the Postfix widget I only see values for Sent, nothing for Rejected etc. - actually I have never seen anything except for Sent.

Emails are being rejected as when I use the Search mail feature I can see entries like this:

Sep 26 10:12:00 wing@cybercatinc.com steve@XXXX.co.uk reject
Sep 26 09:22:16 tejedas@embarq.com steve@XXXX.co.uk reject
Sep 26 09:22:16 tejedas@embarq.com j6g05dt3po6rorq@XXXX.co.uk reject

(the top 2 recipients are valid the 3rd recipient does not exist)

Apologies now, as before I did not give much detail on my setup and now I could be overloading with all the wrong info. :P

Cheers again all and thanks once again for your help.

Bismarck

First in Search Mail > Message Fields: mark all and search again, this will show you much more information. Or even better you login via putty/ssh and watch the logs live:

tail -f /var/log/maillog

Access Lists > Header:
/^Subject:/ WARN
/^From:/ HOLD
/^To:.*@MyDomain.co.uk/ HOLD

scratch that, you have just c&p the example stuff there, this would be a valid list:

#Remove sensitive information from email headers
/^Received: from MTA.LOCAL*/ IGNORE
/^Received:.*with ESMTPS/ IGNORE
/^X-Originating-IP:/ IGNORE
/^User-Agent:/ IGNORE
# SPAM
/^Received:.*rev.sfr.net / REJECT 
/^From:.*@bt.com/ REJECT
/^Subject:.*(Important - BT Digital File):/ REJECT 
# HAM
/^From:.*@XXXX.co.uk / OK

Antispam > After greeting tests: all selected

You may take this into account. (thanks biggsy)

Emails are being rejected as when I use the Search mail feature I can see entries like this:
Sep 26 10:12:00 wing@cybercatinc.com steve@XXXX.co.uk reject
Sep 26 09:22:16 tejedas@embarq.com steve@XXXX.co.uk reject
Sep 26 09:22:16 tejedas@embarq.com j6g05dt3po6rorq@XXXX.co.uk reject
(the top 2 recipients are valid the 3rd recipient does not exist)

Postfix > Access Lists > MyNetworks

Your IPs should be listed here, like:

192.168.0.7 # internal mailhost
192.168.0.1 # pfs lan
127.0.0.1   # pfs loopback

and enable Postfix > Recipients > AD etc..

Cheers! ;)

FlashPan

Thanks for all the info Bismarck. At the moment I'm not using the options uner #SPAM as I'm still; liking to get this tuff generally blocked without manual intervention…great info though for me in the future.

Am not sure why I would want to whitelist google servers? Surely that is only going to effect email coming in from google/gmail and nothing else?

I've added my ip's under Postfix > Access Lists > MyNetworks

Have been sending through some test spam/virus emials but it look like my logs have now randomly corrupted I think as when I search for anything the results are blank or give something starting with Warning: sqlite_query(): no such column: mail_status.info in /usr/local/www/postfix.php on line 606 Warning:

For Postfix > Recipients I've set Custom Valid recipients as I've not installed the p5-perl-ldap package yet.

Cheers again :D

yaboc

my postfix service doesn't stop from the services page and even when i disable the forwarder and rebbot pfsense it seems to be running. im on the current version (pf + package). any ideas why? can i kill it from cli?