advice on spam
Spam often invites you to use a reply facility if you want to be removed from its mailing list. Never do this! The sender will use your reply as an indication that your e-mail address is valid and in use and will therefore send you even more spam.
Likewise, never click on any hyperlink in a spam e-mail because it will track your identity (although an advert blocker such as WebWasher will give you extra protection).
Reputable companies may offer such an "unsubscribe" facility in their e-mails. If you're sure they're reputable, it's okay to reply if you want to unsubscribe.
Junk e-mail — often known as spam — continues to grow alarmingly. It's irritating; it's often offensive; it wastes download time; and it is often used to commit fraud. A special category of spam are those that carry a virus.
My current recommendations
For e-mail pre-processors I recommend MailWasher and POPFile. They are useful if your existing e-mail program doesn't offer spam detection but you want to keep using it. For e-mail software which includes spam detection I recommend the e-mail facilities of the Opera browser; and the Mozilla Foundation's Thunderbird e-mail program.
These are programs that you run before your main e-mail software and which attempt to detect spam. They either allow you to delete the spam or they flag it so that your main e-mail software can deal with it appropriately.
MailWasher deduces which e-mails are likely to be spam using both first-generation methods and second-generation methods. It then enables you to delete these e-mails from your e-mail server. You then run your normal e-mail software, which is therefore not exposed to the deleted spam (or to any viruses they might contain).
Advantages of using MailWasher:-
- You can inspect all your e-mails, including possible spam and virus-bearing e-mails, and decide which e-mails should be deleted.
- It's easy to install.
And the disadvantages:-
- Running MailWasher is an extra step every time you wish to read your e-mail.
- The black-lists and white-lists reduce MailWasher's opportunities to learn what is good e-mail and what is spam and so reduce its learning effectiveness.
MailWasher is a good solution for small amounts of e-mail and spam.
If you receive a lot of e-mail, including spam, I highly recommend POPFile. It uses second-generation methods. When you run your normal e-mail software it accesses your e-mail via POPFile, which flags those it thinks are spam. Your e-mail software can then take appropriate action, such as moving them straight to a spam folder. POPFile classifies e-mail into spam and non-spam but you can set up further categories as well if you wish (e.g. work and home e-mails).
Advantages of using POPFile:-
- You run your normal e-mail software directly — there is no extra step and you don't have to view spam every time.
- POPFile's learning filter is one of the most sophisticated. I am personally achieving 99.8% accuracy with POPFile's classification, which is high enough never to need to examine spam in detail (in case of a wrongly classified genuine e-mail) before deleting it once a week.
And the disadvantage:-
- Although it's not difficult to install, absolute beginners with PCs might not feel confident.
POPFile is freeware, that is, it's free but you are invited to pay a small sum to help pay for its development.
With both MailWasher and POPFile, e-mails, including those containing viruses, are examined as pure data (text) not as executable code, so the risk of virus infection at the pre-processor stage is zero.
All the software recommended will help to detect e-mails containing viruses. But they don't detect viruses explicitly (by virus "signature") and so anti-virus software is still essential.
All of these products have the big advantage that you don't have to install and run a separate pre-processor program.
The first generation of anti-spam software rely on a black-list of suspect words and other suspect characteristics. They may also allow you to create a "white-list" containing, for example, the e-mail addresses of your genuine correspondents. The disadvantages of this method are:-
- the lists have to be constantly maintained;
- the weightings given to each factor are necessarily arbitrary;
- your correspondents' e-mail addresses can be hijacked and included in a "spoofed" From: header, so they are not a guarantee of genuineness;
- Because you don't have full control over the black-list, it's risky having alleged spam deleted automatically — you need to examine it to make sure it's not in fact genuine e-mail.
Some ISPs offer this type of spam filtering at their end. A big advantage is that the spam is not downloaded to your computer, which saves time. ISPs err on the side of caution, so some spam is still let through. Nevertheless, because they only analyse spam but don't analyse the contrasting characteristics of your real e-mail, even innocent-looking genuine e-mails are sometimes classified as spam, so you need to check the spam folder regularly.
As spam constantly evolves in order to evade new detection methods, a second generation of anti-spam software has evolved. They look for characteristics of your genuine e-mail as well as characteristics of your spam. You start to use them in "learning mode" — when they mis-classify an e-mail, you tell them so. They learn very rapidly and their discrimination is based on your particular pattern of "good" and "bad" e-mail. This makes it very difficult for spammers to overcome them.
Look for e-mail software which:-
- includes a folder for spam as well as folders for genuine e-mails;
- enables you to reclassify alleged spam as genuine and vice-versa.
Some ISPs offer this type of spam filtering at their end.
Many spammers and fraudsters buy lists of millions of e-mail addresses and use commercial spamming software to send the spam. The response rate is reckoned to be about 15 per million. If 10 of these 15 people can be persuaded not to respond, that will triple the spammers' costs and help to spare the huge cost and aggravation to the rest of us.
People who respond to spam probably don't install anti-spam software. It's therefore important that all e-mail software should in future include spam detection switched on by default (some ISPs are now adopting the same policy). The second-generation techniques are therefore very appropriate, since they can be "seeded" to work very well even if the user doesn't train them to become even better.