Welcome to the community.
When you send an email message, it will likely travel through a server or two before it get to the recipient. As the email goes from sender to server(s) to recipients, the header of the email gets updated with information containing dates, times, server addresses, etc. Some email clients will track the user's computer that sent the email, some will not. There is no standard. Using this information, assuming the email headers were not forged, one can track who (IP Address) sent the email, what time it was sent, etc. An IP address can be correlated to a physical address using information the ISP can provide.
Your question asks the reverse. How can someone track you by sending you an email? If you reply to the email address, your IP address is likely going to be in the header. If you don't reply, there are tricks one can use to get your IP address. For example, someone can send you an HTML email with a link to an image. Once your email client views that image, the web server hosting the image will track it and record your IP address. This can be further expanded by a simple PHP script that tracks quite a bit of information about your computer, much more than an IP address. There are a few other ways, such as read and delivery receipts, various online services, simple trojans, etc.
I hope this answers your question.