Spammers harvest email addresses in many ways. For example:
- By searching. They use specialized search engines (Spambots) to collect email addresses from web pages, newsgroups, bulletin boards, discussion forums, white & yellow pages, mailing lists, ... etc. automatically.
- By guessing. They can generate a random sequence of characters, hoping to match a few valid addresses.
- By purchasing. They can buy or exchange email addresses from other spammers.
- By having access to some persons' computers through Trojan viruses
- By social engineering. Spammers use a hoax to convince people into giving their email addresses.
- People may be required to submit their email addresses on the Internet (e.g. before downloading some software), and these email addresses may be released to unknown persons.
- People may leave their email addresses in some dubious questionnaire that are found on the Internet, on the street or on telephone.