If you elect, in your profile settings, you can be contactable via Private message, or by email, or both. The Private Message is hosted on this site, and the person never gets your email address. Depending on your settings, and what settings you have in the web browser you use (IE, Firefox, Safari, Google Chrome etc) you can have a pop up box tell you that you have a new PM. If you don't do this, its very likely you will not notice you have a PM, although the board will automatically notify you by email as well.
If you elect to be contacted by email, the board hides that email from web spiders whose sole existence is to find email addresses, and use them for spam. Do not ever put your email address in text in a message. If you really feel it has to be done, hide it by writing it this way yadda at dada dot com dot ca. Best is to leave it to the board, its designed to protect you.
love,
Geoff