PL/SQL UTL_SMTP.HELO

In Oracle PL/SQL, UTL_SMTP is a package that allows you to interact with mail servers through the Simple Mail Transfer Protocol (SMTP). This package is useful for sending emails from PL/SQL programs. One of the key procedures within UTL_SMTP is HELO, which is used to establish a connection between the client (Oracle database) and the mail server by identifying the client to the SMTP server.

Syntax

The UTL_SMTP.HELO procedure sends a HELO (or EHLO) command to the SMTP server, which is an essential part of the SMTP protocol. This command identifies the client’s hostname and initializes the SMTP session. Here’s an overview of how it works:

UTL_SMTP.HELO (
   c        IN OUT NOCOPY UTL_SMTP.CONNECTION,
   domain   IN VARCHAR2
);

c: The connection handle returned by UTL_SMTP.OPEN_CONNECTION, which is used to manage the SMTP session.
domain: A string representing the domain name of the client, which the client sends as part of the HELO command.

Example

The following example demonstrates the use of UTL_SMTP.HELO in a PL/SQL block to establish a connection with an SMTP server and send an email:

DECLARE
   smtp_connection UTL_SMTP.CONNECTION;
BEGIN
   smtp_connection := UTL_SMTP.OPEN_CONNECTION('smtp.example.com', 25);
   UTL_SMTP.HELO(smtp_connection, 'example.com');
   
   -- Additional commands such as MAIL, RCPT, and DATA
   -- would be here to compose and send the email.

   UTL_SMTP.QUIT(smtp_connection);
EXCEPTION
   WHEN OTHERS THEN
      UTL_SMTP.QUIT(smtp_connection);
      RAISE;
END;

In this example:

UTL_SMTP.OPEN_CONNECTION opens a connection to the SMTP server at smtp.example.com.

UTL_SMTP.HELO sends the HELO command to identify the client to the server.

Other SMTP commands follow to send an email (e.g., MAIL, RCPT, DATA).

UTL_SMTP.QUIT closes the connection once the email is sent or if there is an exception.

Notes

Domain Name: It’s important to provide a correct domain name to ensure the SMTP server recognizes and trusts the client.

Security: If your mail server requires authentication, Oracle recommends using UTL_SMTP.AUTH for secure sessions.

Port Configuration: The default SMTP port is 25, but some servers may use port 465 or 587 (SSL/TLS), depending on security configurations.

Using UTL_SMTP.HELO is an initial step in setting up an email session through PL/SQL and forms the foundation for more complex email-sending procedures using Oracle’s UTL_SMTP package.