OS/2 eZine

16 May 2000

Robert Basler is the President of Aurora Systems, Inc.

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dieevilspammersdiediedie @ dontbotherme.com

If you've ever posted on Usenet you've probably seen email addresses like that. Those are people frustrated with spam. If you have posted on Usenet, or filled in a website form, or put your email address on a registration card, or even gone through certain websites, then you probably receive spam yourself - email full of scams, sex, and offers for products and services you just don't want. Post Road Mailer from Innoval Systems, now free for OS/2 users, has some great filtering features that make mail and spam management easy.

Some days I get as many as 70 messages, my busiest day in the last couple of months brought in 131 notes, so some form of automated mail management is a must. Of course not all of that is spam, I am subscribed to a number of mailing lists and get mail from clients and friends, but every day there is invariably some new plan to make me a millionaire or a tempting offer from someone named "Tiffany" or "Kitty." As a business owner, I don't have the time to give each of these "valuable offers" the attention they richly deserve, so in my case, that means they go into the great bit bucket in the sky.

I had been using Ultimail Lite for a number of years and manually deleting spam every day, but when I switched to Warp Server for eBusiness (WSeB) last fall, I found that Ultimail wasn't up to making the transition. It is listed as unsupported for WSeB and everyone I talked to said "it is never going to work, so you may as well pick a new email application." After trying on a few, I decided I liked Post Road Mailer (PRM) the best, and it just happened that PRM had recently been made freeware by its developer Innoval Systems - Thank You!

Filters, Nature's Spam Killers

One powerful feature in PRM is its Filters which can be found in the Features menu. Here is my current list of filters.

Each of these filters is processed one after the other in the order specified in the Post Road Message Filters list. The order of filters is very important, and I'll talk a little more about that in a minute.

Each of these filters is comprised of a number of elements:

Description - A handy name to help you order and organize your filters.

Search String - What the filter should look to find (or not to find) in the note or its headers.

Folder - Where the note should be filed if you don't want to delete it.

Reaction - What to do when the search string is found (or not found) in the area to search.

Search - What portion of the note to search.

Options - Some handy options for the filter.

User Exit Options - Options if you want to use a special external program on the note.

To make a basic spam filter, you need to create a filter (something like this).

The secret to the spam filter is that most automated bulk mail (spam) doesn't bother to put your email address in the "to" field of the note but most mail sent by live people does. The one exception to this rule is notes that are sent to a number of people using multiple To, CC, or BCC addresses, so it isn't a bad idea to file notes in a Junk folder and delete them yourself rather than deleting them automatically as I have done.

As you can see in the picture, this filter looks for my email address in the "To" field of the note. In the Options group, I have selected to React if NOT found so if it doesn't find my email address in the "to" line, the note is rejected as spam and disposed of as I chose in the Reaction box, in this case the note is deleted. If you are nervous about PRM accidentally deleting important notes, create a folder called "Junk" and choose "File Note" to move the potential spam note into your Junk folder to look at later.

You will have noticed that I have quite a number of filters in operation. I receive several mailing lists on topics that I am interested in. To make sure that these automated lists aren't falsely recognized as spam, they have to be filtered out before the spam filter sees those notes. I have created folders for each of my mailing lists, and the filters automatically reroute those notes to the appropriate folders for me so I can read them when I have time. This is where the order of your filters is important, you want to make sure your spam filters are applied last. Fortunately, changing the order of filters is as easy as dragging and dropping them into the position in the list you want.

Another important filter is the Advertisement filter, it looks for the string "ADV:" in the subject line and if it is found, deletes the note. Often spam advertisements are courteous enough to put this string in the subject line.

I also have a number of spammer-specific filters that get rid of those pesky offers from some services that I use (and even some I don't) that have my email address in the "To" field. In these filters, I search each note for some signature such as a domain name in the from field, or in the note body, that is likely to appear in each note, so that I can automatically delete anything received from them.

Spam Reduction Tips

If you are interested in reducing the amount of spam you receive in the first place, here are a couple of tips:

In Netscape, go into Edit, Preferences, Mail & Newsgroups, Identity. Enter a bogus email address for yourself.

Then anytime a website captures your email address, or you post to a newsgroup, the dummy address will be the only one anyone sees, foiling spammers who use these techniques to collect email addresses. If you do this, you will want to consider adding a signature block to any usenet posts with a human readable version of your real email address such as AURORASW AT DIRECT PERIOD CA. Be creative in writing your email address, there is no reason that spammers couldn't take the above and have their programs convert it into a valid email address. Note that if you use Netscape for your email, this tip might not be a good idea.

Never ever, ever, ever respond to a spam note that offers to "remove" you from their list. Many spammers use such replies as indications of people who actually take the time to read their spam and just send more.

Since I have been using these techniques my daily ration of spam has been greatly reduced. Only an occasional note slips through the filters now and I have gone from 10+ spam notes a day to a couple a week. A few other suggestions for reducing spam are:

Apply for a free email address at a service like Hotmail, then use that email address anytime anyone that you probably don't want to hear from again asks for an email address. The address will be valid, but you don't have to look at all the spam you get every day. Note that you'll have to check in with your free email account from time to time to make sure that it doesn't get deleted as a dead account.

You can also fake rejection notices and send those automatically in response to spam. You can do this in PRM by using the Reply to Note option in the Reaction group, but I believe no response is better than an automated response in the long run. A rejection notice might look like:

From: Mail Delivery System <Mailer-Daemon@direct.ca>
Subject: Mail delivery failed: returning message to sender

This message was created automatically by mail delivery

A message that you sent could not be delivered to all of
its recipients. The following address(es) failed:

SMTP error from remote mailer after MAIL FROM:
host mail.direct.ca []:
550 SPAM not accepted

The final alternative is to report repeat-spammers to your ISP. I'm personally not a big fan of this technique since it is a huge time-waster having to forward each spam, and because ISP's tend to take the sledgehammer approach to spam prevention. I have a dealer who I cannot send email to because my domain is blocked on her ISP's mail servers. They did this to block spam from customers of my ISP, but they didn't take into account that my ISP is the largest ISP in Canada with millions of customers, a few of which are bound to be spammers. This would be like blocking aol.com in the U.S.

Most other mail programs also have filters and will be capable of implementing these simple spam-reduction techniques. I hope you enjoy the extra free time.