What causes unsolicited email?
You may receive unsolicited commercial email for a number of reasons.
If you provide your email address to a web site, then that information could be passed to another company. You then may be put on a mailing list for unsolicited email. In general do not provide your email on the internet unless it is a company that you know.
If you sign up for a newsletter that could lead to unsolicited email.
If someone's computer is attacked by a virus or worm, and your email is in their address book, that could lead to unsolicited email.
If you own a web site that could lead to unsolicited email. If you do have a web site, you could decide not to list your email. You could also decide to list it but not make it an active link that visitors could click on.
If you are on a web site filling in a form of some sort, check to see if the URL has a pl, php, or asp. If it does then any information you enter could be captured in a database.