You usually do not want your straight email on a public website because it can be havested by spam-bots. Spambots are software that go out on the web reading web pages. When it finds an email address, it will add that email to the database where a spammer can go and email you bunch of email advertisments. I'm guessing that you usually do not want that.
There are several ways to have an email address that can not be harvested by spam-bots.
1) Use a graphic image of your email address.
2) Use obfuscated form of the email address or munging the email address such as somebodyREMOVETHISBEFORESENDING@somewhere.com.
3) Use a submit form.
4) Use javascript to dynamically generate the email address on the fly. See tutorial here.