Never, ever open an attachment from a suspicious e-mail
It could contain a virus that could wipe out everything on your
PC. To compound the damage, it could duplicate the virus and send
it to everyone in your e-mail address book, potentially destroying
their machines as well.
Don't trust anything in the body of the message
As the saying goes, "There's no such thing as a free lunch."
More ominously, though, there may be inappropriate content or pictures.
Most inboxes are sorted by date, and spammers may get you to notice
their new message by changing the date to several days earlier.
Reply to Sender
From (reply or reply-to address) Similar to the "Sender"
field, the "From" e-mail address is not to be trusted.
It's simply made up. If you attempt to reply, it will either bounce
because the address doesn't exist, or it will go to an innocent
person whose e-mail address was copied without their knowledge.
Name of Sender
Many spammers fake the name of the sender with something innocuous
like "Bob." Is it an e-mail from Uncle Bob? Or maybe from
your co-worker? You don't know, and the spammer counts on your curiosity.
Worse yet, some spammers will fake an e-mail as being from someone
you trust, like a national bank or a well-known online retailer.
If you're lucky, you can identify spam based on its subject line:
You don't need a lower mortgage rate or a date with Trixie. But
more often, spammers use guile to make the subject line something
you might click on. Who hasn't forwarded funny jokes with a subject
line like "FWD: great punchline"?
A new trick is to even fake the "To" or "Recipient"
field. It doesn't appear that the e-mail was sent to you, so the
spammer hopes that you will read it to be helpful and forward it
Clicking a link that promises to unsubscribe you will merely verify
to the spammer that your e-mail address is valid. That verification
means you'll likely be spammed even more.