One picture is worth more than a thousand words. In this post, we will take a look at what happens when Alice sends an email to Bob. 1. Alice logs in to her Outlook client, composes an email, and presses “send”. The email is sent to the Outlook mail server. The communication protocol between the Outlook client and mail server is SMTP.
The Gmail client can also work as a listener for new messages. Thinking that a webhook is present in the client that will be informed (new message event) by the server to fetch the whole message.