create or replace PROCEDURE send_mail (p_to IN VARCHAR2,
p_from IN VARCHAR2,
p_message IN VARCHAR2,
p_smtp_host IN VARCHAR2,
p_smtp_port IN NUMBER DEFAULT 25)
AS
l_mail_conn UTL_SMTP.connection;
BEGIN
l_mail_conn := UTL_SMTP.open_connection(p_smtp_host, p_smtp_port);
UTL_SMTP.helo(l_mail_conn, p_smtp_host);
UTL_SMTP.mail(l_mail_conn, p_from);
UTL_SMTP.rcpt(l_mail_conn, p_to);
UTL_SMTP.data(l_mail_conn, p_message || UTL_TCP.crlf || UTL_TCP.crlf);
UTL_SMTP.quit(l_mail_conn);
END;

execute send_mail(p_to => 'recipient_email',p_from => 'sender_email',p_message => 'This is a test message.',p_smtp_host => 'SMTP_HOST_NAME',p_smtp_port=>25);

PL/SQL procedure successfully completed.