Spammers often disguise their email in an attempt to evade anti-spam software. Increasingly spam arrives via legitimate email addresses whose user credentials have been compromised, from services like Yahoo!, Hotmail and AOL.
Scammers are also targeting large email service providers (ESPs) with malware in an effort to compromise their mail transfer agents (MTA) in order to send spam.
Spam is often profitable. Spammers can send millions of emails in a single campaign for very little money. If even one recipient out of 10,000 makes a purchase, the spammer can turn a profit.
Does spam matter?
- Spam is frequently used to distribute malware.
- Spammers often use other people’s computers to send spam .
- Spam, like hoaxes or email viruses, uses bandwidth and fills up databases.
- Users can easily overlook or delete important email, confusing it with spam.
- Spam wastes staff time. Users without anti-spam protection have to check which email is spam and then delete it.
Spammers are now also exploiting the popularity of instant messaging and social networking sites such as Facebook and Twitter to avoid spam filters and to trick users into revealing sensitive and financial information.