Be Cautious with E-mail

The best way of dealing with e-mails from an address you don't recognise is to discard them completely. That way, they can't cause any harm to you or your machine.
You should never open an e-mail attachment from anyone you don't know. The attachment could easily be a virus or some kind of objectionable material - this is one of the commonest ways in which viruses are spread.
Many e-mail programs prevent users from opening attachments with any kind of "active" content, ie: anything which runs a program or script which could damage your computer.
You should also avoid following hyperlinks in e-mail messages from anyone you don't know, as they can lead to web sites which will infect your system with a virus or spyware, or display objectionable material.
Finally, never reply to unwanted emails. That simply lets the sender know that your e-mail address is genuine and is likely to lead to more unwanted emails in future.