Eressea Server Down

The Eressea server (and with it, this blog) has been down for about a week due to a burnt motherboard. The hard drives could be saved, but the new machine doesn’t have SCSI, so some work had to be done. Thanks go to Andreas and Nils for fixing this.

The new machine is no longer Debian but Ubuntu. This gives me a chance to set things up The Right Way – after 8 years, the old machines had a lot of quirky stuff installed, and was running with a number of unexplained anachronisms. So excuse the mess, we’re under construction.

Here’s my preliminary TODO-List:
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Study: 95% of all e-mail sent in 2007 was Spam

CNET reports,

There was a time – 2004 to be precise – when spam “only” consumed 70 percent of all e-mail. Those were the good old days. Today, as Barracuda Networks’ annual spam report shows, upwards of 95 percent of all e-mail is spam.

Personally I think those numbers are skewed. Barracuda is a professional provider of spam blocking, and their customers are businesses that can afford to install a dedicated machine for spam filtering. We had one at Funcom. Me on the other hand, I don’t have one of those. And at least judging from myself, I’m less likely to enter my home email address into a form than my work email.

Still, 95% is insane. Spam processing is probably the major part of what my server is doing. About 2-3 of them every day make it through my SpamAssassin and end up getting filtered by the Thunderbird rules or myself. Some years ago I set up an automated process that takes the Junk folder on my IMAP server and teaches it to SpamAssassin so that it learns from the mistakes it made, so I’m staying ahead of the deluge.

Could everybody please stop buying from these people so they give up?

read more | digg story

Thunderbird + Gravatars = Letdown


So I found the nifty gravatar extension for Thunderbird, and after making it work in 1.5.0.*, I was anxious to see how many of my contacts actually have a Globally Recognized Avatar. On first glance, I couldn’t find any. Well, so maybe not very many people have one?

So I went and wrote a little script that would go through my archived mails and address book, checking every sender’s gravatar. The result is shocking: Except for myself, there was only 1 (ONE!) other address, and that was the one for the Firefox newsletter (and yes, that has a firefox logo).

So while it’s a nice extension, it’s widely unused. So are X-Faces, so installing an extention for those is almost as useless. Too bad. I’m a visual person, and I would like seeing avatar icons with mail 🙂

web.de, IMAP und Thunderbird

Was IMAP angeht, bin ich ja immer skeptisch. Aber bei web.de scheint das gut zu klappen. Habe eben ein HOWTO geschrieben für Einrichten von web.de Accounts in Thunderbird (mit IMAP). Auch wenn es das sicher schon irgendwo geben wird…

Privat benutze ich übrigens dann doch weder IMAP noch web.de noch einen deutschen Thunderbird. Englischer Thunderbird und mein eigener POP3 Server. Ein sinniger IMAP-Server (mit maildirs) wäre allerdings mal ein Projekt.

Enno, there’s a .dat attachment on your emails!

No, that’s not a virus. And no, there’s nothing with a .dat attachment on my emails, even though Outlook Express wants you to believe it. It’s a digital signature. It looks like this:

Content-Type: application/pgp-signature

-----BEGIN PGP SIGNATURE-----

Version: GnuPG v1.2.2-nr2 (Windows XP)

Comment: Using GnuPG with Thunderbird -http://enigmail.mozdev.org

iD8DBQE/fSqo2FTH6fnzT0IRAv81AJ42L5GD3XrqN0Sv/

ksXaKvcOCuQhgCeOlgy9FaROdCRoGB3Qd6lunjKDvk=

=NHUe

-----END PGP SIGNATURE-----

What it does is to confirm that this email is actually written by me, and noone tempered with it. It’s like putting my signature under a written letter, only more safe against tampering.

Why is this such a problem for some people? Outlook Express. This degenerate piece of shit software decides that “if I don’t know what it is, I’ll make it look funny, invent an extension for it, and oh, while I’m at it, I’ll also not show my user the plain-text parts that I *could* understand, but pretend it’s in a .txt file attachment. And on the default security settings, it removes them:

If you’re an Outlook Express user, this is pretty annoying. But trust me, the mails from Outlook Express users are painful, too – and not because of a fault in anyone’s mailtool but the sender’s. So if it’s okay for the OE users to send their non-standard borked emails, I don’t see why I should stop sending my perfectly standdard-compliant emails just because OE doesn’t want to handle them.

“But Enno”, you’ll say, “don’t you care about whether people can read what you write?”. Yes I do. But the people I really care about are tech-savvy, and they don’t use mailtools that are old and broken. The standard for MIME (RFC 2048) will be 7 years old next month, and standard for OpenPGP/MIME (RFC 2440) will be 6 years old by then. They were practically invented before Microsoft realized that the Internet was something that mattered to them. Plenty of time to implement them. And about time to shrug, shake your head and go on with life. OE is dead.

Spam, paranoid mail scanners

Somebody is using forged email addresses in the eressea-pbem.de domain to send out spam. Since I’m the postmaster for that domain, all the undeliverable mails land in my inbox – or they did, I’m now filtering on them.

There was one real gem among the replies. This stupid mail scanner rejected the mail not because it was spam, but because it contained the word online. That’s paranoid. I’d hate to be one of their users, really…

Thunderbird problem

I was upgrading enigmail today, and after restarting Thunderbird, it gave me the message that “A previous install did not complete correctly. Finishing install”. I googled for a fix, then helped myself: Whenever the file C:\Program Files\Thunderbird\xpicleanup.dat exists, Thunderbird will give the message. I deleted it, and Thunderbird starts. Not sure if I broke something in the process, though. The newer enigmail version didn’t install, and any time I tried, it gave the error again. the final solution was to remove my chrome/ folder from c:\Documents and Settings\enno\Thunderbird, delete the xpicleanup.dat file, delete and reinstall Thunderbird, then reinstall all extensions. A hassle, but at least now I’ve got a clean and working mail client again.

Spam Assassin und exim richtig konfigurieren

Der Eressea-Server hat die letzten Tage ein echtes Problem damit gehabt, all meine Spams zu filtern. Was ist passiert? Meine private Email läuft über den Account, und ich bekomme einen Menge Spam. Auf meinem alten Uni-Account lagen letzte Woche z.b. 2200 Mails, von denen etwa 15-20 kein Spam waren.

Um dem ganzen Herr zu werden setze ich Spam Assassin ein. Das Programm ist super. Leider braucht es relativ viel CPU, und der Eressea-Rechner ist nicht grad schnell. Auf einer der beiden PPro 200 CPUs dauert es 40 Sekunden, eine Mail von 126 Zeilen zu bearbeiten. Irgendwann, bei einer Load jenseits von 100, hat der Rechner keinerlei Speicher mehr gehabt, er hat ja eh nur 64 MB + Swap. Und an dieser Stelle fängt Linux dann an, Prozesse in Notwehr abzuschiessen. Irgendwann lief nix mehr, und Andreas mußte physikalisch an die Maschine heran. Danke, Krawi!

Was habe ich gelernt?

1. Lass andere die Arbeit machen.

Es ist nicht gut, alles in Spam Assassin zu füttern. Die Uni Paderborn hat auf ihrem Mailserver einen eigenen Spam Assassin laufen, und den werde ich von jetzt an zumindest einen Teil der Arbeit machen lassen. Alle Mail, die über meine eigenen Domains laufen, kommen aber weiter ungefiltert zu mir. Ich benutze nebenher meinen Account bei despammed.com für alles mögliche, wo ebenfalls eine Menge für mich vorgefiltert wird.

2. spamd einsetzen

Spam Assassin kann man als Daemon starten, und das tue ich jetzt. Statt dass er jedesmal seine Konfiguration und Regeln neu laden muss, wird im Fall einer anfrage dann wirklich nur die Mail bearbeitet. In meinem Fall senkt das die Verarbeitungszeit von 40 auf etwa 25 Sekunden herunter. Immer noch eine Menge.

3. spamd richtig konfigurieren.

Ich habe mehrere Optionen angeschaltet, um spam assassin zu beschleunigen: --local --max-children 10 --auto-whitelist. Außerdem habe ich die Bayes Filter abgeschaltet (Eintrag in user_prefs: use_bayes 0)

4. exim richtig einstellen

Mein Problem wurde vor allem dadurch verschärft, dass ich mit fetchmail in regelmäßigen Abständen sehr viele Mails auf einmal bekommen habe, und exim dann für jede Mail einen procmail-Prozess gestartet hat, der wiederum einen Spam Assassin startete. Plötzlich liefen hunderte Prozesse, die alle versuchten, das gleiche Lock auf meine Mailbox zu bekommen. Das ging nicht gut. Ab heute ist mein exim so konfiguriert, das er ab einer Load von 4 keine Mails mehr auszuliefern versucht. Das geht mit den Parametern queue_only_load und deliver_load_max in der exim.conf.

Jetzt bete ich mal, dass das alles ist, und der Rechner bis zum Wochenende überlebt.