Answer:


When it comes to delivering and storing mail on a receiver server, the protocol that is commonly used is the Simple Mail Transfer Protocol (SMTP). SMTP is responsible for sending outgoing mail from the sender's server to the recipient's server. It is a standard protocol used for email transmission over the internet.


SMTP is designed to handle the delivery of email messages. It operates on the application layer of the TCP/IP protocol suite and uses a client-server model. Here's how SMTP works:

1. Connection Establishment: The email client (sender) establishes a connection with the email server (SMTP server) on port 25.

2. Handshaking: The client and server exchange a series of commands and responses to establish a connection. This includes the identification of the client and server, as well as the negotiation of supported features and security options.

3. Email Transfer: Once the connection is established, the client sends the email message to the server using SMTP commands. This includes the sender's email address, recipient's email address, subject, and the contents of the email.

4. Mail Delivery: The server verifies the email addresses, checks for spam or security issues, and then attempts to deliver the email to the recipient's server.

5. Error Handling: If there are any errors or issues during the email transfer process, SMTP provides error codes and messages to help diagnose and resolve the problem.

6. Store and Forward: SMTP supports the concept of "store and forward," meaning that if the recipient's server is unavailable or offline, the email can be stored on the sender's server until the recipient's server becomes accessible. Once the recipient's server is available, the email will be delivered.


In summary, SMTP is the protocol responsible for delivering and storing mail on a receiver server. It provides a reliable and standardized method for sending email messages over the internet. By following the SMTP protocol, email clients and servers can communicate and ensure that email messages are successfully delivered to the intended recipients.