Complexity

— complexity —
Needs Documentation

— complexity —
Just Right

— complexity —
Just Right

— complexity —
Just Right

— complexity —
Needs Documentation

— complexity —
Just Right

— complexity —
Just Right

— complexity —
Just Right

— complexity —
Just Right

— complexity —
Needs Documentation

— complexity —
Needs Documentation

— complexity —
Just Right

— complexity —
Needs Documentation

— complexity —
Needs Documentation

— complexity —
Just Right

— complexity —
Too complex

— complexity —
Just Right

— complexity —
Just Right

— complexity —
Just Right

— complexity —
Just Right

— complexity —
Needs Documentation

— complexity —
Too simple

— complexity —
Just Right

— complexity —
Just Right

— complexity —
Too simple

— complexity —
Just Right

— complexity —
Needs Documentation

— complexity —
Just Right

— complexity —
Just Right

— complexity —
Just Right

— complexity —
Just Right

— complexity —
Needs Documentation

Recent Posts

Mail Server Attacks

     With the recent surge in spam, I wanted to let everyone know what you can do, what I am doing, and the amount of attacks our mail server is under.

First, what you can do:

        1) Send spam you receive to: spamtrap@eskimo.com

        2) Send some non-spam examples to: hamtrap@eskimo.com

     This trains the Bayesian filters to recognize spam.  Without examples of non-spam as well, the filters can not differentiate, so it is important to send some non-spam to hamtrap@eskimo.com as well, especially anything that is not spam but gets dropped in your spambox.

     You can adjust your spam filters to better suit your needs: Click For More Info

What I am doing:

     Spam filtering and spammers working to get past filters is an ongoing continuous struggle.  Spammers test their spamming algorithms against spam filters and refine them.  Developers alter spam filters to take spammers new methods into account.

     Like our web server previously was, our mail servers are based upon CentOS6.  CentOS6 was current in 2012, but although not yet at end of life, it is no longer the latest and greatest and getting little developer attention.  Consequently updates are infrequent and spam filtering lags behind spammers.

     I am working to move the mail servers to Ubuntu 15.10, as I have recently with the web server.  Not only will it insure frequent and current updates but it will also improve performance somewhat.

Mail Server Attacks:

     So that you can appreciate the amount of probing our mail server gets, people looking to find ways to find valid addresses to spam, I thought I’d share the current fail2ban IP block list.  This is just what is hitting the server today:

Chain f2b-dovecot (1 references)
target     prot opt source               destination         
REJECT     all  --  173-165-112-17-Illinois.hfc.comcastbusiness.net  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  245.24.188.61.broad.dy.sc.dynamic.163data.com.cn  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  153.ip-51-255-33.eu  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  185.56.80.114        anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  104.43.229.232       anywhere            reject-with icmp-port-unreachable 
RETURN     all  --  anywhere             anywhere            

Chain f2b-dropbear (1 references)
target     prot opt source               destination         
RETURN     all  --  anywhere             anywhere            

Chain f2b-pam-generic (1 references)
target     prot opt source               destination         
RETURN     all  --  anywhere             anywhere            

Chain f2b-postfix (1 references)
target     prot opt source               destination         
RETURN     all  --  anywhere             anywhere            

Chain f2b-postfix-rbl (1 references)
target     prot opt source               destination         
RETURN     all  --  anywhere             anywhere            

Chain f2b-postfix-sasl (1 references)
target     prot opt source               destination         
REJECT     all  --  173-165-112-17-Illinois.hfc.comcastbusiness.net  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  245.24.188.61.broad.dy.sc.dynamic.163data.com.cn  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  153.ip-51-255-33.eu  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  185.56.80.114        anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  104.43.229.232       anywhere            reject-with icmp-port-unreachable 
RETURN     all  --  anywhere             anywhere            

Chain f2b-recidive (1 references)
target     prot opt source               destination         
REJECT     all  --  185.56.80.114        anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  37.49.226.186        anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  windows66101.geoffery.com  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  58.221.44.205        anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  76.72.173.181        anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  164.39.136.123       anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  190.52.32.172        anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  D-128-208-148-212.dhcp4.washington.edu  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  ip-184-168-146-234.ip.secureserver.net  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  c-98-247-175-109.hsd1.wa.comcast.net  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  97.75.89.35          anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  mail.tdsconstruction.com  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  91.108.176.107       anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  h88-150-206-217.host.redstation.co.uk  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  hosted-by.rdparena.com  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  host69-2-static.24-87-b.business.telecomitalia.it  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  fbh226.internetdsl.tpnet.pl  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  g141198.upc-g.chello.nl  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  163.115.broadband.iol.cz  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  p509988fd.dip0.t-ipconnect.de  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  76.72.173.190        anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  mail.servprowmsn.com  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  75-150-98-233-NewEngland.hfc.comcastbusiness.net  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  75-146-243-98-Philadelphia.hfc.comcastbusiness.net  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  s18429360.onlinehome-server.com  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  u15969958.onlinehome-server.com  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  static-72-248-8-166.ny.onecommunications.net  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  rrcs-71-40-142-130.se.biz.rr.com  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  static-71-190-170-117.nycmny.fios.verizon.net  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  cpe-70-92-233-170.wi.res.rr.com  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  70.35.206.123        anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  70.35.201.19         anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  70.35.195.55         anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  69.197.155.50        anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  host-69-146-169-202.static.bresnan.net  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  c-69-141-167-235.hsd1.nj.comcast.net  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  static-68-238-246-15.phlapa.fios.verizon.net  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  mail.lundinroof.com  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  68-115-153-234.static.hckr.nc.charter.com  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  c-67-183-32-47.hsd1.wa.comcast.net  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  h-67-102-220-137.lsan.ca.megapath.net  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  windows76978.kesto.com  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  nsc66.147.31-180.newsouth.net  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  host2.deltagalil.com  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  65.127.84.206        anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  dsl-112-24-rb.jax.centurytel.net  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  mail.illuminatingexpressions.com  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  rdp02.snthostings.com  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  61.233.62.179        anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  61-230-101-27.dynamic.hinet.net  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  58.221.58.187        anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  58.221.55.243        anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  58.221.46.247        anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  58.221.44.252        anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  58.218.185.110       anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  58.181.246.173       anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  ec2-54-169-158-59.ap-southeast-1.compute.amazonaws.com  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  ec2-54-153-96-21.us-west-1.compute.amazonaws.com  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  50.37.2.54           anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  50.34.210.34         anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  50-242-183-98-static.hfc.comcastbusiness.net  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  50-192-1-249-static.hfc.comcastbusiness.net  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  50.116.122.101       anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  static.203.51.9.5.clients.your-server.de  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  mail4.midiasphost.com  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  46.29.254.236        anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  46.29.252.123        anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  46.29.248.155        anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  host.de.appvz.com    anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  ip-222-106.dataclub.biz  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  41.57.23.150         anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  40.118.240.189       anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  37.49.226.136        anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  37.203.213.2         anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  abs-static-146.4.251.27.aircel.co.in  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  rrcs-24-97-142-18.nys.biz.rr.com  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  rrcs-24-199-162-14.midsouth.biz.rr.com  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  24-117-238-66.cpe.cableone.net  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  23-95-114-42-host.colocrossing.com  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  mx1.closurepac.com   anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  216.154.10.117       anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  application-31240.pck.nerim.net  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  sip.quranradio.qa    anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  212.107.104.132      anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  207.201.206.162      anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  206.72.196.23        anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  202.155.213.54       anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  201.190.7.150        anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  79.201-148-26.bestel.com.mx  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  199.187.125.62       anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  199.187.123.100      anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  199.180.118.241      anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  199.180.118.240      anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  199.180.114.251      anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  198.50.201.15        anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  198-0-1-133-static.hfc.comcastbusiness.net  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  197.221.63.185       anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  195.245.173.70       anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  195-154-47-128.rev.poneytelecom.eu  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  192.99.222.112       anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  192-3-13-36-host.colocrossing.com  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  191.101.23.229       anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  static-190-181-38-244.acelerate.net  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  Static-IP-19015924092.cable.net.co  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  udf.life.com.br      anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  189.22.180.178       anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  188.244.138.162      anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  fixed-191-28-168.iusacell.net  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  187-11-116-244.dsl.telesp.net.br  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  186.3.197.5          anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  186-238-50-114.customer.tdatabrasil.net.br  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  185.3.134.123        anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  185.3.134.120        anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  185.3.134.111        anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  185.3.134.103        anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  185.3.133.64         anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  185.3.133.39         anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  185.3.133.146        anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  185.121.132.143      anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  mo-184-6-80-235.dhcp.embarqhsd.net  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  184-23-195-114.dedicated.static.sonic.net  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  183.71.75.140        anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  183.60.111.212       anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  mail.hazemag.in      anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  181.49.47.145        anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  static-181-143-131-58.une.net.co  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  180.111.230.246      anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  179.184.46.199.static.gvt.net.br  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  179.127.166.63       anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  178.216.49.147       anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  176.61.140.125       anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  176.61.140.12        anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  176.61.140.101       anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  175.100.68.220       anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  wsip-174-79-249-61.sd.sd.cox.net  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  D-173-250-191-187.dhcp4.washington.edu  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  48.architel.com      anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  ool-addcd752.static.optonline.net  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  173.214.175.19       anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  173-167-168-247-illinois.hfc.comcastbusiness.net  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  173-11-171-233-houston.txt.hfc.comcastbusiness.net  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  172.76.109.167       anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  164.77.47.16         anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  162.248.76.217       anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  162-17-222-125-static.hfc.comcastbusiness.net  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  158.69.57.241        anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  155.254.17.236       anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  142.54.162.197       anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  D-140-142-128-197.dhcp4.washington.edu  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  D-140-142-128-144.dhcp4.washington.edu  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  14.139.249.85        anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  14.102.52.163        anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  datco2000.serverlet.com  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  D-128-208-186-77.dhcp4.washington.edu  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  D-128-208-148-71.dhcp4.washington.edu  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  125.67.126.89        anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  120.141.68.130       anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  cr002ex02.couristan.com  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  118.70.81.79         anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  14.115.2.109.rev.sfr.net  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  108.59.46.114        anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  D-108-179-135-158.dhcp4.washington.edu  anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  107.182.20.207       anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  107.151.227.205      anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  104.243.24.149       anywhere            reject-with icmp-port-unreachable 
REJECT     all  --  static-100-13-135-9.tampfl.fios.verizon.net  anywhere            reject-with icmp-port-unreachable 
RETURN     all  --  anywhere             anywhere            

Chain f2b-sogo-auth (1 references)
target     prot opt source               destination         
RETURN     all  --  anywhere             anywhere            

Chain f2b-sshd (1 references)
target     prot opt source               destination         
RETURN     all  --  anywhere             anywhere            

Chain f2b-sshd-ddos (1 references)
target     prot opt source               destination         
RETURN     all  --  anywhere             anywhere            

Chain f2b-uwimap-auth (1 references)
target     prot opt source               destination         
RETURN     all  --  anywhere             anywhere            

Chain f2b-xinetd-fail (1 references)
target     prot opt source               destination         
RETURN     all  --  anywhere             anywhere            

Chain f2b-xinetd-fail-log (0 references)
target     prot opt source               destination         
LOG        all  --  anywhere             anywhere            limit: avg 6/min burst 2 LOG level warning prefix `f2b-xinetd-fail:DROP ' 
REJECT     all  --  anywhere             anywhere            reject-with icmp-port-unreachable
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