Stamp out spam emails

How to spot spam
Identifying spam amongst legitimate emails is made trickier because spammers commonly use a technique known as spoofing to retain their anonymity.

Spoofing makes it appear that an email has been sent from a completely different email address to the one it has really been sent from.

The spammer changes the information attached to the email – called the header – that shows where it originated from to make it look like the email has been sent by someone else.

Sometimes this email address is non-existent, but sometimes the spammer will have guessed at an email address that is actually in use. So the first the real owner of the email address knows about it is when they receive irate, and often not particularly polite, messages from strangers demanding they stop spamming them.

Be aware that it’s not just the name at the start of an email address – the Joe.Bloggs bit – that can be spoofed. Looking for a credible or recognised domain – the bit after the ‘@’ – in the From: line of an email isn’t enough to guarantee its authenticity. Spammers are also able to spoof domains, which is why in a phishing scam, the fraudster can pose as a company the recipient does business with.

However, there are various hallmarks of spam emails that can be used collectively to help identify spam. In unsophisticated cases, the email address in the From: field is often a bit of a mess, containing an email address that is often just a random string of letters and numbers followed by a webmail domain.

For instance, sf3ffwr23w@hotmail.com. Let’s face it, that wouldn’t be your first choice when signing up to an email service. Also look out for email addresses that appear to have been sent from different email addresses, but have identical subject lines or ones that make no sense.

While the majority of email programs have built-in spam blockers, there will be the odd piece of digital junk that repeatedly breaches security and makes it into your inbox. In this case, the most effective means of prevention is to block emails arriving from a specific sender or domain, also called a fixed address. To do this in Outlook Express, click on a message from the sender that you want to block. Then, in the Message menu, click Block Sender. Now any email you receive from this sender will automatically find itself in your Deleted Items folder.

Adding names to the Block Sender list in Outlook produces the same result, but requires a slightly different process. Click Options within the Tools menu and, on the Preferences tab, under E-mail, click Junk
E-mail. Now click the Block Sender tab and then Add. Within the box ‘Enter an e-mail address or Internet domain name to be added to the list’, type in the offending email address, then click OK. Alternatively, right-click the unwelcome email and click Junk E-mail to add the sender to the Block Sender List.

Get your settings on-side
Thunderbird users can also customise how junk email is received and dealt with. If the Junk filter is enabled (go to the Tools menu, then Account Settings, then Junk Settings, then ‘Enable adaptive junkmail controls for this account’), all suspicious email will carry a green junk icon, leaving you the choice of deleting it, or clicking the button ‘This is not Junk’.

In the case of the latter, future emails from that sender won’t be treated as spam. Within the Junk Settings menu there are further options to move new spam to a Junk folder (recommended) automatically and to delete junk mail older than a specifiable amount of time. To prevent trusted emails being marked as junk, there’s also the option to ‘Not mark mail as Junk if the sender is in your personal address book’.

It’s also possible to train Thunderbird to identify what’s spam and what’s not. To do this effectively, you’ll need to mark all mail as either Junk or Not Junk by right-clicking the message and selecting the corresponding option from the list. The associated keyboard shortcuts are J for Junk and Shift and J for Non Junk. And the more you teach Thunderbird, the more Junk will automatically find its way into the Junk folder. Don’t forget to check the Junk folder occasionally to ensure it’s doing its job properly.