Hi, Phil. If you want email notifications have a look at the bottom of the web page. If you're looking at the page for one of the forums there will be a "Subscribe to forum" link at the bottom. If you're looking at a page for a thread it will say "Subscrive to topic". Click on that and when a new post is made to the forum or thread you've subscribed to an email will be sent to the address you have on file in your account. However, you will only get one email per topic until you visit the web site and read the forum or thread you've subscribed to.
If you want a running stream of the conversations like used to happen when the list was email based and hosted off Topica then the best option is to subscribe to the RSS feed here:
http://www.streetphoto.info/forum/rss.phpHowever, in order to reply to a post you'll need to go back to the web site. The RSS posts come with a link directly to the thread in question, so it's pretty easy to do.