Send mail from PL/SQL

Send mail without attachments using the UTL_SMTP package: 

DECLARE
  v_From      VARCHAR2(80) := 'oracle@mycompany.com';
  v_Recipient VARCHAR2(80) := 'test@mycompany.com';
  v_Subject   VARCHAR2(80) := 'test subject';
  v_Mail_Host VARCHAR2(30) := 'mail.mycompany.com';
  v_Mail_Conn utl_smtp.Connection;
  crlf        VARCHAR2(2)  := chr(13)||chr(10);
BEGIN
 v_Mail_Conn := utl_smtp.Open_Connection(v_Mail_Host, 25);
 utl_smtp.Helo(v_Mail_Conn, v_Mail_Host);
 utl_smtp.Mail(v_Mail_Conn, v_From);
 utl_smtp.Rcpt(v_Mail_Conn, v_Recipient);
 utl_smtp.Data(v_Mail_Conn,
   'Date: '   || to_char(sysdate, 'Dy, DD Mon YYYY hh24:mi:ss') || crlf ||
   'From: '   || v_From || crlf ||
   'Subject: '|| v_Subject || crlf ||
   'To: '     || v_Recipient || crlf ||
   crlf ||
   'some message text'|| crlf || -- Message body
   'more message text'|| crlf
 );
 utl_smtp.Quit(v_mail_conn);
EXCEPTION
 WHEN utl_smtp.Transient_Error OR utl_smtp.Permanent_Error then
   raise_application_error(-20000, 'Unable to send mail: '||sqlerrm);
END;
/

Send mail with attachments using the UTL_SMTP package: 

DECLARE
   v_From       VARCHAR2(80) := 'oracle@mycompany.com';
   v_Recipient  VARCHAR2(80) := 'test@mycompany.com';
   v_Subject    VARCHAR2(80) := 'test subject';
   v_Mail_Host  VARCHAR2(30) := 'mail.mycompany.com';
   v_Mail_Conn  utl_smtp.Connection;
   crlf         VARCHAR2(2)  := chr(13)||chr(10);
BEGIN
  v_Mail_Conn := utl_smtp.Open_Connection(v_Mail_Host, 25);

  utl_smtp.Helo(v_Mail_Conn, v_Mail_Host);

  utl_smtp.Mail(v_Mail_Conn, v_From);

  utl_smtp.Rcpt(v_Mail_Conn, v_Recipient);

  utl_smtp.Data(v_Mail_Conn,
    'Date: '   || to_char(sysdate, 'Dy, DD Mon YYYY hh24:mi:ss') || crlf ||
    'From: '   || v_From || crlf ||
    'Subject: '|| v_Subject || crlf ||
    'To: '     || v_Recipient || crlf ||

    'MIME-Version: 1.0'|| crlf || -- Use MIME mail standard
    'Content-Type: multipart/mixed;'|| crlf ||
    ' boundary="-----SECBOUND"'|| crlf ||
    crlf ||

    '-------SECBOUND'|| crlf ||
    'Content-Type: text/plain;'|| crlf ||
    'Content-Transfer_Encoding: 7bit'|| crlf ||
    crlf ||
    'some message text'|| crlf || -- Message body
    'more message text'|| crlf ||
    crlf ||

    '-------SECBOUND'|| crlf ||
    'Content-Type: text/plain;'|| crlf ||
    ' name="excel.csv"'|| crlf ||
    'Content-Transfer_Encoding: 8bit'|| crlf ||
    'Content-Disposition: attachment;'|| crlf ||
    ' filename="excel.csv"'|| crlf ||
    crlf ||
    'CSV,file,attachement'|| crlf || -- Content of attachment
    crlf ||

    '-------SECBOUND--'   -- End MIME mail
  );

  utl_smtp.Quit(v_mail_conn);
EXCEPTION
  WHEN utl_smtp.Transient_Error OR utl_smtp.Permanent_Error then
    raise_application_error(-20000, 'Unable to send mail: '||sqlerrm);
END;
/