How does SMTP handle email messages?

SMTP, which stands for Simple Mail Transfer Protocol, operates primarily on a push model for sending email messages. In this model, when an email is sent, the sending mail server directly transfers the message to the recipient's mail server using SMTP commands. This process involves establishing a connection to the recipient's server and pushing the email through that connection, thereby ensuring that messages are delivered in a timely manner and reaching their intended destination.

The effectiveness of SMTP lies in its ability to relay messages across networks from the sender's mail server to the recipient's mail server efficiently. It is particularly important in the context of email transmission, where the reliability of delivering messages is a crucial aspect of its functionality. Therefore, SMTP is fundamentally designed as a protocol to deliver rather than to retrieve or store messages, distinguishing its operations from other email protocols that are used for managing messages after they have been received.

In contrast, options that suggest retrieving emails or using a pull model describe the functions of other protocols, such as POP3 or IMAP, which are designed for accessing and managing email stored on a server after it has been sent. These protocols function differently, focusing on how users access their email rather than how it is initially sent.