Will >> Will's blog

purpose: Will Kahn-Greene's blog of Miro, PyBlosxom, Python, GNU/Linux, random content, PyBlosxom, Miro, and other projects mixed in there ad hoc, half-baked, and with a twist of lemon
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Thu, 13 Jul 2006

SPF and Exim in Debian

Turns out the Debian packager doesn't enable SPF in the exim4-daemon-heavy package. But it took me a couple of hours to figure that out. I ended up implementing SPF using the libmail-spf-query-perl package by adding the following rule to my rcpt acl just before greylist stuff:

  accept
    message     = [SPF] $sender_host_address is not allowed to send mail \
                  from $sender_address_domain.
    log_message = SPF check failed.
    set acl_m9  = -ipv4=$sender_host_address \
                  -sender=$sender_address \
                  -helo=$sender_helo_name
    set acl_m9  = ${run{/usr/bin/spfquery $acl_m9}}
    condition   = ${if eq {$runrc}{0}{true}{false}}

The exit codes for spfquery are in the spfquery file (it's a Perl script) and the code for "pass" is 0. So (in theory) this will accept any email that passes the SPF check. Any email that fails the SPF check will go through greylistd. I think that does what I want it to do.

Incidentally, I found the above code (though I inverted the check) here at The Linux Documentation Project.

Tue, 14 Mar 2006

Greylisting and whitehosts-list

Gah... For some reason, I've got two whitehosts-list files on my system. One in /etc/greylist/ and the other in /var/lib/greylist/ .

It's also interesting to note that the greylistd doesn't look at either file, the files are used by rules in the Exim configuration. So when I added the gmail items (64.233) to whitehosts-list and then tried to check it with greylist check --grey ... I was using the wrong checking tool. Whoops! 30 minutes down the drain!

Anyhow, once I discovered that whitehosts-list is in the Exim configuration files (and I should have realized that because I put it there) and not checked by greylistd, I discovered that the Exim configuration files check both copies of whitehosts-list. There's likely a good reason for that. Probably even my fault to begin with. Something to look into when I have some spare cycles and feel like pouring through Exim configuration, Debian policy for directories and configuration files, and all the other pieces in between.

Sat, 11 Mar 2006

greylisting and gmail

I have greylistd installed (on Debian with exim) and noticed last monday (March 6th) that Google has something like 26 outgoing SMTP servers for gmail. That doesn't work well with greylistd, though. So I added "64.233" to the whitehosts list. Not sure if that's the right thing to do or not, though. I'm not wildly excited about adding items to the whitehosts list.

Mon, 16 May 2005

"tyranny of email"

I was skimming jkOnTheRun [1] and he linked to an article called The Tyranny of Email. The article isn't very exciting, but there were a couple points that caught my eye because they're crappy things that I keep doing but shouldn't be. For example:

"First, never, ever, criticize someone in email. For reasons which I have never fully grasped, any negative emotion is always amplified by communication through email. Sometimes you intend to be critical - someone has done something dumb, or said something silly, or emailed something ridiculous. Resist the urge to reply. Sometimes you don't mean to be critical - you're just making an observation, or engaging in technical debate, or adding facts to a discussion. But as soon as you sense that the recipient has taken your email as criticism, you must immediately switch media - a face-to-face meeting is best, but a 'phone call is also okay."

Also this one (less so):

"Second, don't get into prolonged technical debates in email."

Usually, the "technical debates" I get into over email are less "technical" and more hyperbole. All hyperbole is bad! [2]

[1] Every time I look at "jk", I think he's just kidding. It's confusing.

[2] j/k

Fri, 29 Oct 2004

Marketing emails

First off, most marketing emails are annoying. Having said that, it's amazing at how many companies can't get their act in gear and send emails that are encoded and formatted properly. I suspect many of these companies hire some email-marketing company to do the dirty work for them--and it surprises me more that the "professionals" can't get it right.

Companies who totally screw it up: Crucial, Antec (I can't even make out what they're yammering about), Alienware and... hrm... I can't think of the other ones that annoy me. I'll have to update this entry later.

Companies who get it right (at least for the emails I'm getting): Amazon.com, TopCoder (they send a lot of email), Sun Microsystems, ThinkGeek, 1-800-flowers, and CDBaby.

Tue, 20 Jul 2004

Too much data

I have data issues. I have email going back to 1996 and I have documents and other data formats for which I don't have the original program anymore.

In regards to email, every now and then I get up enough energy to start going through it and deleting email that's clearly not interesting. The problem here is that I accumulate more email than I delete and I feel like I spend a lot of energy and time organizing it.

In regards to the other data, I could keep moving it from format to format but that also takes a lot of energy and time.

I don't keep a journal or a diary, so this data is really the only records I have of past years. It's the only way I can get a glimpse of how I've grown over time.

The question is how important is this data? Is it important to keep it all, or is it good enough to just keep a few things that capture enough of the essence of that period of time? Is it better to go through things and create an "editorial" of that period of time with citations from the original pieces and then destroy all the original data?

What uses does the data have? Maybe it's better to just jettison it all and start afresh?

Sun, 02 May 2004

Added comments to my site

I added comments to my site for two reasons:

  1. I needed to test out the instructions for installing comments in PyBlosxom.
  2. I needed to become more familiar with the comments system since people ask a lot of questions about it.

Anyhow, they seem to be installed and working well. Hoorah.

Tue, 03 Feb 2004

My theory about interacting on the Internet

If you want to do these things, write them in a private journal. You know--one of those paper kind.

Thu, 06 Nov 2003

There isn't a do-over

The problem with voice mail is this: as you're leaving a voice mail for someone and you suddenly slip and say something really tawdry, you can't take it back--it's there forever. This is the subject of occasional HI-larious subplots in various movies. But the sobering fact is that this can happen in real life as well.

So, if you're going to leave a voice mail, think it through before you start babbling incessantly. There is no do-over.

Tue, 02 Sep 2003

Ways to avoid spam

This is an ongoing essay which will collect a series of links and thoughts on how to avoid spam. Avoiding spam is a way of life, not something you think about today and then forget about for a few years.

Update 12/9/2004: There is no way to avoid spam anymore. You can probably reduce it by not telling anyone anything, but every second that your email address exists increases the likelihood that you'll start getting spam.