blog.iloaf.com » Knee Jerk

Mailchannels first impressions & its feedback loop

Chris — Sun, 25 May 2008 22:09:22 +0000

I love the idea of abusing the fact that spammers are in a hurry. Traffic Control checks all the geeky check-boxes of a SMTP proxy I should take a closer look at.
So the first thing I do once I can netcat to the proxy and check it’s running is fire up a “tcpflow -c -i eth0 not port 22” to watch it in action. I could immediately see how it slows connections (sweet), and then the instant phone home traffic or feedback mechanism.
I’m not so sure I like the feedback mechanism. The main issue is “but not be limited to” statement in the license as usual not the fact that they aggregate logs, over http on port 25.

Exhibit #1 – License snippet :

17.Feedback. The Software may periodically submit statistics about its
operation to servers operated by MailChannels and other parties
authorized by MailChannels (the “Feedback”). The Feedback shall
include but not be limited to the IP addresses of email senders,
server memory usage, server CPU usage, and various attributes of
email sending hosts such as operating system type.

Exhibit #2 – Stream capture : feedback.mailchannels.com port 25 gets sent a log line per email as a http post.

rd.42946-feedback.mailchannels.com.00025: POST /et/capture HTTP/1.1
Host: feedback.mailchannels.com
Content-Length: 402
Connection: keep-alive

[2008-05-25 16:58:53 +0100] [22019] i=78.149.112.169:52371 h= o=N u= a= t= p=0 d=0
x=”ClientACL t=0,0|EarlyTalker t=0|RBL action=reject;cbl.abuseat.org=no_data;hul.habeas.com=no_data; query.bondedsender.org=no_data;sbl-xbl.spamhaus.org=no_data; t=0.11,0.17,0.04,0.28,0.17;zen.spamhaus.org=127.0.0.11.reject”
l=ACCEPT c=550 z=”Found on zen spamhaus” e=”[550,Found on zen spamhaus]”
q= n=1/0/1 b=0/0/0/1 v=

^{CR’s added for readability}

I completely understand why they want the spy-in-the-box (having worked with Justin I know the possibilities are endless) but that license is a bit too lax for me. It’s just a niggle but I’d feel more comfortable if it was defined explicitly, and explained in full and have the option to disable it on privacy grounds.

You need to disable SPF in your mailserver too, since the postfix sees the proxy ip, spf hard fails result in a reject … I should have thought of that Maybe thats where my license file has gone Woops.

Just in case Ken reads this..

Kudos for the non commercial licensing

I’ve mailed free-beer and am still waiting for a key.

Being a typical old school QA guy I’ve a heap of suggestions, but for the time being this image of my mailbox shows the performance in the first hour or two with the default config.

...eww, but you should see what happens without it.
In fact if you look at the graph below you can see the effect is that the server is relaying more mail and rejecting less.

^{E&OE plus the fact I’m in a rotten mood, I’m blaming the prescription(s)}

cottages4you (aka VRG) suck

Chris — Wed, 02 Jan 2008 11:27:09 +0000

I hope you all had a better festive season than me. -4 degrees on Christmas morning with a broken boiler in the heart of northern France wasn’t much fun. We perceivered for a couple of nights with the loan of some crappy electric heaters and a temperamental example of French home wiring. We had to give up when the elder family decided it was way too cold and enough was enough.

I’m going to cause a lot of pain for somebody at cottages4you today – their emergency numbers were off-line for the duration of our troubles.

Update: c4u customer care are now in the office and have been very responsive. If only they could have been like this out of normal hours.

Update #2: Situation resolved. c4u do not deny our situation and their errors and have resolved matters accordingly.
The out of hours services need to improve. It still sucks that cottages4you’s emergency numbers were offline (not even voicemail based callback) on bank holidays. They really need to step it up a gear and make sure that phone is covered 24h 365.25days a year for big issues. Being an agent for a contracted landlord is no excuse and does not prevent them being liable for issues since thats who the customer has a contract with at the end of the day.

Having sobered up from the rugby…

Chris — Thu, 24 Mar 2005 04:14:34 +0000

.. It’s back to knee jerk reality with a bump. It’s stupid’o’clock and I can’t sleep.
I should probably explain this category at this point.

“Knee-Jerk”; Synonyms: absence of thought, automatic reaction, gut reaction, involuntary impulse, Pavlovian response.
(Strangely rarely the latter ;))

So Knee-Jerk is something thats done for the sake of doing something, usually when that something had no good reason to be fscked with in the first place (one misunderstood), often as a verbal reaction whilst (pea or chemically abused) brain is clearly in neutral but one felt the need to be seen to verbalise something.

(usually when they can’t stand the awesome power of pause/silence that is generally used part way thorough a sentence whilst the speaker waits for your penny to drop (NB: g!=9.81 inside bags of water and protein)). Feel free to comment with other examples

Back to the category; It has nothing in-particular to do with flora, fauna, family, work, life, the universe and everything I would like to add. It is just situations, however big or small that were caused due to memory corruption in a sentient being.

We all do it from time to time but most of us twig and apologise

It’s been a fun week, 2 steps forwards followed buy a step back, but fun all the same.
...3 back in CNN’s case. (It’s just a challenge response gizmo, They are not new or costly (they just suck).
So they win today’s award of the coveted Knee-jerk trophy. (Quiet news day, had to say something about IBM’s ~~old~~new toy, fscked up with foot in mouth and brain is clearly in neutral).

It’s nice to know some people get paid to think rather than talk.

We all loved RFC 1321 (even if you didn’t know you did)

Chris — Sun, 13 Mar 2005 08:59:17 +0000

Don’t start any FUD please, this attack can be thwarted since it requires you know the templates of the certificates and as most serial numbers are long enough randoms or created via a secret, this will mostly foil this as I understand it.

Internet spurs poor quality software

Chris — Sat, 05 Mar 2005 21:59:15 +0000

Test Bed has some good points about the “ship it quick, patch it later” culture that follows some (not all) Internet focused software. Internet spurs poor quality software

In the past, console games have always been more stable than PC games, in general, because they are not easy to patch. If a company releases a screwed up console game itâ€™s a lot more detrimental because a customer cannot go download patch.

...T-Shirts for sale, Get ya Quality T-Shitrs ere. Quality is after all an investment right?