What is the function of an email?

digital message sent electronically from one computer to one or more other computers. Emails are flexible and can be used for giving instructions, serving as documentation, providing confirmation, communicating rules and procedures, making recommendations, providing a status update, making an inquiry.

The function of an email is to contact your peers. Email lets you talk and colaborate with people from all over the world, not just your city or country. It's also convenient on many electronic devices. There are multiple platforms that make a site to email people.