What application layer protocol does electornic mail transfer use

Electronic Mail Transfer (EMT) is a protocol that is used to transfer email messages between email servers. The application layer protocol used by EMT is Simple Mail Transfer Protocol (SMTP).

SMTP is a protocol that is used to send and receive email messages between email servers. It is a push protocol, meaning that the sender's email server initiates the transfer of the email message to the recipient's email server.

Here's a high-level overview of the process:

1. The sender's email client (e.g. Microsoft Outlook) sends the email message to the sender's email server using SMTP.
2. The sender's email server breaks the email message into smaller chunks and sends each chunk to the recipient's email server using SMTP.
3. The recipient's email server receives the chunks and reassembles the email message.
4. The recipient's email server stores the email message in the recipient's mailbox.

SMTP is a widely used protocol for email transfer and is supported by most email servers and clients.