Stop spam!

Are you getting too much spam? (Here we're talking about the unwanted e-mail kind of course!)

There are plenty of spam-fighting products available. Some products work only with certain e-mail programs (for example Outlook, Outlook Express, or Thunderbird. Some come with a one-time cost, some require an ongoing subscription. They employ a variety of spam-fighting techniques. It's worth knowing how a product works before buying one, or even before installing the (usually free but time-limited) trial product, so you don't waste time on something that doesn't meet your needs.

Programs or plug-ins that work entirely on your computer. This capability may already be built into your e-mail program! For example Thunderbird has a junk mail filter built-in. You can also buy add-ins to do this kind of filtering; an example is ella for Spam Control. These spam filters use one or both of two techniques: Adaptive filters and sender lists.

Adaptive filters attempt to "learn" the difference between good and bad e-mail. Ads for these anti-spam products may include words like "heuristic" or "Bayesian". Usually you train the filters by using them to sort through your e-mail. As you mark items as spam or not spam, the filters analyze the messages to look for patterns that they will use to classify future incoming messages. The main shortcomings of this anti-spam techique include the risk of overtraining and the changing nature of spam.

Overtraining happens when you mark too many messages as spam: You've seen those messages that have little or no mention of any product or service, just lots of meaningless words or sentences. The spammer is using those words and sentences to get past the filters. As you mark those messages as spam, you are training the filter to reject messages that look like English text, which makes the filters less effective at recognizing messages you really do want to receive.

The other problem with "learning" filters is that they don't keep up with the changing nature of spam. On the simplest level, you try to train the filters to reject misspelling of "viagra" or "pharmacy", but you've probably noticed there seem to be an infinite variety of misspellings, including the use of spaces and punctuation. You've also seen spam that contains one big picture of words, with noisy dots and slanting text to prevent software from detecting the words in the picture. Spammers know all the anti-spam tricks, and are continually working to get around anti-spam systems.

Sender lists are used in many anti-spam products. This involves sorting your messages into approved senders and blocked senders. The anti-spam software might add a "block this sender" button to the mail program. However, you've probably noticed that spam often comes from a different sender every time, so the blocked sender list is of little use.

Some anti-spam products work by implementing an extreme form of sender lists, called challenge and response: Every incoming e-mail is assumed to be unwanted unless the sender is already in your "approved" list. Everyone else is sent a message that requires them to verify that they are a real person in order to have their message delivered. This method is highly effective at reducing unwanted e-mail because spammers don't respond to the challenge. Unfortunately, it's also annoying to legitimate senders, since it delays the arrival of their message to you and takes more action on their part. It's also more work for you: You'll probably end up looking through the blocked messages to see if "good" messages are stuck there. If you frequently receive mail from unexpected senders (for example if you hope new clients will contact your business via e-mail) then challenge and response is probably not for you. Spamarrest is an example of a challenge and response system.

Another anti-spam technique involves installing software that makes your computer part of an anti-spam network. Examples of this type of software is Cloudmark, formerly known as Spamnet, and Spamfighter. This software consults a central anti-spam server to learn what the newest spam looks like. As other users of this software mark messages as spam, that information gets reported to the central server. When your e-mail program downloads your mail, it compares it to the information on the server to decide if the message looks like spam. It's like other people are training your computer to recognize spam! This spam-fighting method keeps itself up-to-date with the latest spam techniques. Disadavantages of this technique are that it requires a fast internet connection to consult the anti-spam server and that a monthly subscription to continue getting the latest spam profiles.

In summary, there are a lot of anti-spam products which use a variety of strategies to cut down on spam. The best product for you depends on which e-mail client you use, how you use e-mail (e.g. do you have a close circle of friends or do you want to get mail from new senders), and whether you want to pay for ongoing services.

- JB

Creating PDF files

Do you need to create PDF files? You could spend $129 or more for Adobe Acrobat Standard, Pro or 3D. Or, you can create PDF's for free!

PDF output is built in to OpenOffice.org, the free alternative to Microsoft Office. OpenOffice.org (which everyone I know just calls "Open Office") can read and write Microsoft Office files, and, unlike Microsoft Office 2007, looks and works a lot like Office 2003.

You can also make PDF files from just about any program you run on Windows. Download PDFCreator from here or here, install it, and "print" the document.

At the point where you can choose a printer, choose PDFCreator instead. Your "print" will go into a PDF file instead of to hardcopy. Anyone with Adobe Acrobat Reader should be able to read it.

PDFCreator will present a bunch of options as you create the file. This is entirely for your own benefit. If you don't care about adding metadata to the document, just click Save.


Lastly, you'll see a file selector where you choose the name of the output file. This is the PDF file you can keep or send to others.

- JB

Access your data from anywhere on your network

Do you have more than one computer on your home or small office network? Would you like to share your data between these computers?

The two best solutions for this need are to set up Windows Simple File Sharing or set up a Network Attached Storage (NAS) device.

With Windows File Sharing you make a folder on one computer available to other computers on your network. The other computer(s) can read and (if you allow it) write to this folder. You can, if you wish, do this on each of the computers so that each one is sharing one or more folders, or you can let all the computers use the shared space on only one computer (the server).

Setting up Windows File Sharing is beyond the scope of this article. Plenty of web sites describe setting up file sharing, including PracticallyNetworked.com and Microsoft.com.

One of the disadvantages of using a general purpose computer as your file server is that computer must be up all the time -- or, at least, any time you might want to access your files! If you're going to have something running all the time, you might be better off with a special-purpose, simple, energy-efficient server: A Network Attached Storage, or NAS, device.

A NAS device is dedicated to providing data storage space for computers on your network, and giving access to the data stored on that device. NAS devices can be purchased for as little as under $100, or as much as several thousand dollars. Spending more money typically gives you more reliability, more storage space, and faster data transfer. For a typical small office, a $200 to $400 investment in hardware can give you basic file storage and retrieval, file sharing, and data backup capability.

"But wait," you say, "why can't I just use one of those inexpensive USB hard drives for storage and backup?" You can do that, but USB drive space isn't easily shared between computers. You can share them with Windows File Sharing, but then you're back to the situation where you need to keep the general purpose computers running to access the data attached to them. What's more, many of the external USB disks spin constantly rather than idling down when they are not being used, so your disks are likely to wear out faster. Where will you be when your data backup device fails?

There are roughly four classes of NAS products:

1. Very simple network devices to which you add external USB drives. These are inexpensive units (about $100) but you still need to add the cost of USB drives. They generally do not let the disks spin down when they're not being used. Example: The Linksys NSLU2.
2. Simple NAS boxes that allow you to insert your own drives. These typically cost $100 to $200 plus the cost of the drives you add. These are more likely to let the disks spin down when not in use. Examples: D-Link DNS-323 and Linksys NAS200.
3. Simple NAS boxes that come with their own internal drives. Typical cost: $130 to $500 depending on storage capacity. Examples: The Western Digital My Book World Edition and the Buffalo LinkStation series.
4. Business-class NAS units designed for high availability, high capacity, and high speed. These typically cost over $1000, and will not be covered in this article.

There are plenty of sites on the web that describe various Network Attached Storage (NAS) products. Examples are:

• An informative Network Attached Storage article on Wikipedia,
• NAS reviews by ExtremeTech.com,
• Plenty of information and reviews at SmallNetBuilder.com (click on NAS)

As you research NAS products, look for these attributes:

• Standard file sharing protocol, usually identified as SMB/CIFS. Bonus if the description specifies Macintosh and/or Linux compatibility.
• Energy saving capability, sometimes referred to as Automatic Power Management, that spins down the disks when not in use.
• Transfer speed. Manufacturer and store web sites often don't mention this; you'll need to read the reviews or performance comparisons. Also, read closely to see if they are report megaBITS per second or megaBYTES per second. 8 megabits is equal to 1 megabyte.
• Storage capacity, which also affects price. 1000 MB (megabytes) is 1 GB (gigabyte), 1000 GB is 1 TB (terabyte). For estimating your storage needs, a typical digital photo may be 2 MB, a recordable CD holds 700 MB, a typical recordable DVD holds about 4 GB.
• Whether backup software is included with the system.
• Other capabilities, for example connecting a printer to the same device.

There is yet another option for local network storage: Just about any computer can be turned in to a dedicated NAS device by replacing the general purpose operating system with NAS software. 3 leading software NAS implementations are: NASlite, FreeNAS, and ClarkConnect. (ClarkConnect is actually a full-featured server operating system.) This solution is more suitable for the technically inclined. One of its pluses is that it can make use of hardware you already own!

- JB

Repair your TV remote!

Are the buttons on your TV remote control becoming harder and harder to press? Have some of the buttons stopped working at all? Remote controls with these symptoms are surprisingly easy to fix.

Here are things to try:

1. Replace the batteries (OK, you probably thought of that)
2. Buy one of those "Universal Remotes" from Target or your local drug store. This is an easy "fix" if it works with your device.
3. You can actually fix your remote control. Here are instructions: http://www.keypadrepair.com/

Here's what's going on:

Most remotes have a rubber sheet thingy that pokes through the holes in the top of the remote, making it look like you have lots of separate buttons. The underside of this rubber sheet has a thin coating of electrically conductive paint sprayed on it. This coating can wear off, particularly on those frequently used keys like power on/off, channel, and volume control. All you have to do is open your remote control, clean off the circuit board contacts with rubbing alcohol, and maybe add a little conductive paint to the bottom of those buttons.

In the photo, see the black rectangle? That's the underside of the rubber sheet. Nickel Print has been applied to six of the rubber buttons. The other buttons worked, so I didn't mess with them.

Tips:

• You can test your remote control buttons from the comfort of your workbench. Turn on your digital camera, point it at the front of the remote, and press a button on the remote. The normally invisible infrared light shows up nice and bright in your camera screen! This shows you whether the button is working. If some buttons work and some don't, it's time to refurbish your remote.
  
• When disassembling your remote, look for little screws on the back or inside the battery compartment that may need to be removed.
• Use a dull knife or a small screwdriver to pry the two halves of the remote apart. (For my remote, it worked to start prying at the battery compartment.)
• Clean the spilled soda and other corrosion on the circuit board with rubbing alcohol. Let it dry before reassembling.
  
• Test your remote using the digital camera trick or with your television. If it works, you're done! Otherwise it may help to repair the conductive surface on back of the rubber keys.
  
• You can order the special paint from the web site shown above, or you can go to your local electronic parts specialist and ask for "conductive paint". This kind of paint is used to repair circuit board traces. It has a high concentration of metal, usually silver or nickel. I found a product called Nickel Print (by MG Chemicals) at Norvac Electronics for about $5.

Caveat: Attempt this at your own risk. There is a possibility that you might further damage your remote, or injure yourself with a sharp or dull tool, or inhale too much fumes from the cleaner or from the paint, or something else may go wrong. Use your own good sense when considering or attempting this procedure. This repair worked for me, there is no guarantee it will work for you.