databases of spam senders and heuristics to decide what is junk. They continually update themselves, downloading the latest “spam signatures” (similar to virus signatures) to recognize new spam campaigns.
Another important role
of security software is to protect you from the nastier side of spam. Not all spam is just annoying: some emails or messages contain country email list phishing links or malware. Antivirus programs scan email attachments and clicked web links.
Explains step by step how phishing works
Even the smartest people can fall for a good modern security suites phishing attack. Source
If you happen to open a suspicious attachment from a spam email, your antivirus can quarantine the file before it causes any problems. Likewise, if fax list you click on a link that leads to a known fraudulent site, many Internet security suites will block the site and warn you.