What is pull protocol in SMTP. Give some examples?

The pull protocol in SMTP (Simple Mail Transfer Protocol) refers to the method by which an email client retrieves messages from a mail server using protocols like POP3 (Post Office Protocol version 3) or IMAP (internet Message Access Protocol). In this context, the client "pulls" messages from the server to access them locally. For example, a user might configure their email client to use POP3, which downloads emails and often removes them from the server, or IMAP, which allows for syncing messages across multiple devices while keeping them stored on the server.