Your email should be on every page in case your students need help. This will tell your browser what to expect and will therefore decrease the loading time of the page. If you leave them out, the browser defaults and expects a large image every time. Don't simply take text, convert it to html, and paste it into webpages. The web allows for interactivity - take advantage of the ability to insert images, hyperlinks, video streaming, and more.
Straight text is hard to read on the web, and students quickly lose focus.