What command is used to signal the end of an email body in SMTP?

In SMTP (Simple Mail Transfer Protocol), the command used to signal the end of an email body is a single dot (.) on a line by itself. This is part of the SMTP protocol's specification, which defines how email messages are formatted and transmitted.

When sending an email, after the sender has included the message body, placing a single dot on a new line informs the SMTP server that the message content has concluded. This signaling mechanism ensures that the server can correctly interpret where the message ends, which is crucial for proper processing and communication.

The dot convention also accommodates various mailing systems and ensures compatibility, thus maintaining the integrity of message transmission across different email platforms. Understanding this command is fundamental for anyone working with email protocols, as it directly impacts how messages are structured and delivered.