A major problem that users often encounter is a variety of malicious software that spreads through the Internet, such as viruses, worms, and Trojan horses. Viruses may infiltrate through security holes in your web browser, but they most often come to your mailbox attached to e-mail messages. The contents and subject lines of these e-mail messages can contain randomly generated rows of text or word combinations, but they often attempt to arouse your curiosity and entice you to open the attached files. As soon as you open an attached file, a virus infects your computer, scans your address book, and then sends itself to everyone on your address book on your behalf. Aside from distributing themselves, the viruses may steal your private information, collect and report information on your browsing habits, exploit your machine for running a heavy spamming campaign or a Denial of Service attack (DoS), create a backdoor for remote management of your computer, and do lots of other nasty things that you would not like.
To defend your system from viruses, do not open suspicious e-mail attachments, enable anti-virus protection on the server side, if this service is provided by your hosting company, and be sure to have a firewall and anti-virus software installed on your personal computer. Also keep your operating system up-to-date and timely install security hot fixes and patches.
To switch on anti-virus protection for a mailbox:
When an infected e-mail message arrives, the appropriate notice is sent to the mailbox owner and the message is placed into a quarantine directory on the server. Only the server administrator can view infected messages stored in the quarantine directory.
To switch off anti-virus protection for a mailbox: