Email is handled via a process called SMTP – Simple Mail Transfer Protocol.
Emails can be written and sent via the email client (ex. Outlook).
It is then sent from your
hosted email server…
… to the recipient's server via the MX records in their domain's DNS.
Email is received from sender.
Your email is managed by software called email clients.
Some of the most popular clients include Microsoft Outlook, Gmail, Mac Mail, Mozilla Thunderbird, and the native applications on your iPhone, Android and Blackberry devices. In addition to interacting with the server, these applications often let you manage additional related functions such as contacts and calendars – but those details aren't typically managed on the mail server.