If you make a mistake as you type an SMTP command, you need to press Enter, and then type the command again. Unrecognized SMTP commands or syntax errors result in an error message that looks like this: 5.
This optional command lets you view the characters as you type them, and it might be required for some SMTP servers. This optional command enables logging and specifies the log file for the Telnet session.
If you only specify a file name, the log file is located in the current folder. If you specify a path and file name, the path needs to be on the local computer, and you might need to enter the path and file name in the Windows DOS 8. The path needs to exist, but the log file is created automatically. In this example, you're requesting a DSN message for successful or failed message delivery. This section provides information about the success and failure responses to the commands that were used in the previous example.
SMTP servers respond to commands with a variety of numerical reply codes in the format of x. When a response is received by the server that opened the connection, it can tell whether the remote server accepted the command and is ready for the next one, or if an error occurred. The first digit X is particularly important to understand because it indicates the success or failure of the command that was sent.
Here are its possible values, and their meanings. Additional information, including descriptions of the second Y and third Z digits of SMTP reply codes is included in this section, and in sections 4. Successful response : mail1. Failure response : Connecting to mail1. Could not open connection to the host, on port Connect failed. ESMTP servers can advertise their capabilities during the initial connection.
These capabilities include the maximum accepted message size and supported authentication methods. Possible reasons for failure : The destination server doesn't accept anonymous message submissions. You receive this error if you try to use Telnet to submit a message directly to a Mailbox server that doesn't have a Receive connector that's configured to accept anonymous connections.
Skip to main content. This browser is no longer supported. Download Microsoft Edge More info. Contents Exit focus mode. Is this page helpful? The ENVID parameter allows the client to attach an identifier that will be transmitted along with the message.
The purpose of the ENVID is to allow the sender of a message to correlate the original message with any DSNs that are received for that particular message. DSN messages are used within T. For instance, if a fax is converted to an e-mail by the onramp gateway and it is configured for DSN, the delivery status of the mail message containing the TIFF attachment of the fax is sent to the user specified in the gateway configuration.
Example shows an actual DSN message indicating successful delivery of a fax-mail sent by the mail server to the user specified in the configuration of the onramp gateway.
Another notification to the sender that can prove useful is message disposition notification MDN messages. The difference between DSN and MDN is that DSN messages notify the sender of message delivery status by the mail server, whereas MDN messages notify the sender about how the already delivered message is processed by the recipient.
For example, although a DSN will notify the sender that the mail message has been successfully deposited in a user's mailbox, it does not mean that the user has viewed the message. An MDN takes the process a step further and informs the sender when the recipient has actually opened the message. An MDN is often referred to as a "read receipt" or a "return receipt" because it informs the sender that the mail message that was sent was opened by the recipient.
The address in the "Disposition-Notification-To:" field identifies where the disposition notification should be sent. Example illustrates the header for an e-mail that was delivered to the recipient [email protected]. This header requests that an MDN be sent to the sender [email protected]. Notification-To: [email protected].
Because an MDN reveals to the sender whether and when a recipient has opened the mail message, it is sometimes considered an invasion of privacy. Because of these privacy considerations, MDN support is not available in several mail clients. If it is supported, it is typically implemented in such a fashion that the recipient is explicitly asked whether to acquiesce to the MDN request by the sender. For instance, when the recipient of the e-mail in Example opened that mail message, his mail reader requested for him to accept or deny the sender's request for a read receipt to be sent back.
The recipient agreed to the request, and the MDN shown in Example was sent. From: [email protected]. Now that the DATA command has been sent we can start sending the message contents.
This starts with the various headers. At minimum a message should contain a to, from, subject, and date header. The headers entered here will be shown to the user in their email client. This is done with a period on a line by itself. If during the writing of a message a period on a line by itself is needed, you must put 2 periods, the first escaping the second. Lastly the QUIT command is sent to close the connection:. With that the mail server has now accepted the message for delivery, and it should be sitting in the inbox of the RCPT TO address!!!
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