Social networks

Workgroup list of 3 computers

Now, there’s a happy sight: all 3 main computers at Potting Shed HQ happily talking to one another on the local area network.

The two laptops (Gareth-laptop and Jane-laptop) are both running Windows 7 Release Candidate (build 7100), the desktop (Study) is still running Windows XP SP3.

At first my laptop wouldn’t appear in the list of workgroup PCs on the study PC, and vice versa — although each could ping the other and connect successfully by entering the UNC address (e.g. \\computername\foldername). I wondered if it was an issue with the NodeType setting in the registry.

As soon as I changed the NodeType setting on the XP machine it was picked up on my laptop. It could very well be co-incidence but I’m not complaining.

A reboot of all three PCs certainly didn’t do any harm.

So … I wish I could have categorically reported what I did to make it work, but as with so many things in life it appears that all I had to do was switch it off and switch it back on again.

For humans, I believe, they call that ‘sleep’. I’m retiring to bed now to switch myself off for the duration of the night.

Are you listening Reuben and Joshua? 😉

Recycled grunge

Recycled Nirvana
Recycled Nirvana

Last week I was looking for something on Amazon UK, I can’t remember what exactly, and stumbled on this rather incongruous pairing in Amazon’s “Frequently bought together” feature:

  • 3 x Proteam recycling bags
  • 1 x Nirvana (greatest hits) CD

I wonder how many times something needs to be bought together to qualify for Amazon’s definition of frequently bought together.

Cut up your credit cards the right way

One of the most useful devices I have in my study is my trusty Fellowes cross-cut shredder.

Sadly it’s not quite so hardcore that it handles CD-ROMs or credit cards but here’s a video to show you how to cut up your credit cards so that they cannot be used to glean any personal data from it.

Dealing with spam

Junk E-mail folder

There’s a really interesting article in this month’s PC Plus magazine about the war against spam which gave me the impetus to try to do something about those annoying spam messages that appear in my inbox with my email address in the ‘from’ field, like this:

123greetings.com [[email protected]]

Anti-spam software

I use Cloudmark Desktop, a spam blocking add-in for Microsoft Outlook 2007. It’s unobtrusive and pretty reliable, eliminating about 99% of all spam that gets delivered to my inbox. (In the last 4 days I’ve received 166 junk mail messages.)

But it has been those last 1% of messages that have been really annoying me these last few weeks, the ones that have been sent out to look as though they have come from my email account.

So I did a bit of investigating and have discovered a way that I can also send those messages to the Junk E-mail folder while retaining those emails that have genuinely been sent my myself (test emails or those that I’ve CC-ed or BCC-ed to myself for archiving purposes).

Outlook rules

Like most email clients Outlook allows you to define rules (sometimes known as filters).

Rules help you manage your e-mail messages by performing actions on messages that match a specific set of conditions. After you create a rule, Microsoft Outlook applies the rule when a message arrives in your Inbox or when you send a message.

1. Rules and Alerts…

In Outlook 2007 you can access the rules wizard by going to Tools > Rules and Alerts…

Outlook rules

Not surprisingly, this brings up the Rules and Alerts window:

Rules and Alerts

2. Email headers

And now for the science bit… It occurred to me that I needed to create a rule that did two things:

  1. Flag any emails that have my email address in the sender’s address.
  2. Check to see if I really did send those or not.

So within any message supposedly sent from myself I needed to look for some kind of unique value that could prove to Outlook that I really did send those emails. For that information I turned to the email headers.

In Outlook 2007 these are located on the Options panel, by clicking the tiny arrow at the bottom right of the panel:

Viewing Internet headers in Outlook 2007

As well as the information that you can immediately read within an email there is a lot of hidden data, known as ‘headers’, also transferred with each email; information such as where the email message was sent from, its return path (where the email should be sent if the recipient presses “Reply”).

Here’s an example from a random item of spam I received yesterday:


X-POP3-From: [email protected]
Return-path: <surveyingxq @rossiter.com>
Envelope-to: [email protected]
Delivery-date: Mon, 12 Oct 2009 13:17:47 +0100
Received: from laubervilliers-000-11-22-33.w444-555.abo.wanadoo.fr ([123.145.156.178]:25793 helo=SpeedTouch.LAN)
by server.mymailhost.co.uk with esmtp (Exim 4.54)
id 1MxJqT-0000Xc-4O
for [email protected]; Mon, 12 Oct 2009 13:17:46 +0100
Received: from 123.145.156.178 by mail.rossiter.com; Mon, 12 Oct 2009 14:17:43 +0100
Message-ID: <[email protected]>
From: "123greetings.com" <gareth @garethjmsaunders.co.uk>
To: </gareth><gareth @garethjmsaunders.co.uk>
Subject: You've received a postcard
Date: Mon, 12 Oct 2009 14:17:43 +0100
MIME-Version: 1.0
Content-Type: multipart/mixed;
boundary="----=_NextPart_000_0006_01CA4B36.00064AD0"
X-Priority: 3
X-MSMail-Priority: Normal
X-Mailer: Microsoft Outlook Express 6.00.2900.2180
X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2180</gareth></surveyingxq>

I can immediately identify a number of values here that prove to me that I didn’t send this email:

  1. The return-path is wrong. It’s not set to my email address. (With some testing, however, I discovered that this isn’t a reliable field to check against as some spammers also populate this with the email address they send the email to, i.e. yours!)
  2. The HELO value is also wrong — “HELO” is the SMTP command that the sending machine uses to identify itself to the receiving machine — it should be set to the network name of my PC, which for arguments’ sake we’ll call ‘GARETH-PC’.
  3. The X-Mailer value is also wrong. I don’t use Microsoft Outlook Express.
  4. I also noticed that this email didn’t have an Organization set in the headers. Now I know that I have set the organization information in my email account, so that’s another value I can check for.

So against any of these four items I can check any message that has been supposedly sent to me and determine whether I really have sent it or not.

3. My rules

So I have built up my rule piece by piece to read:

Apply this rule after the message arrives
with [email protected] in the sender’s address
move it to the Junk E-mail folder
except if the message header contains ‘helo=GARETH-PC’ or ‘my_alternative_isp.com’ or ‘Organization: My organization name’

And that’s it. Remarkably, it seems to work quite effectively. In the last few days that I’ve been using it I’ve had only 1 spam message left in my inbox. Everything else has been suitably and efficiently whisked away to the Junk E-mail folder. Long may that continue.