Question
There are many stages or clauses in a typical SMTP transaction such as…
- Initial server connection
- HELO/EHLO
- RCPT
- DATA
- EOM
What exactly is referred to as EOM?
Answer
The DATA clause is used to indicate that the sending server is now ready to
transmit the body of the message proper, having already provided the
delivery information via the MAIL and RCPT clauses. The sending server
indicates that it has completed the sending of the body of the message by
sending the EOM signal.
The EOM signal consists of a CRLF followed by a “terminating” dot followed by another
CRLF (CRLF indicates a new line, i.e. a Carriage Return immediately
followed by a Line Feed, the equivalent of pressing the Enter key on most
operating systems)
When the receiving server detects the EOM process it will issue a “250 OK” acknowledgment. Once this has taken place we know that the sending server has sent the e-mail, it will then shortly after, proceed to close the connection.
See Also:
- What is the SMTP HELO/EHLO clause?
- What is the SMTP DATA clause?
- What is the SMTP MAIL clause?
- What is SMTP?
Keywords:SMTP EOM End of message