SQL> declare
  2        lConnection UTL_SMTP.CONNECTION;
  3  begin
  4        --lConnection := UTL_SMTP.OPEN_CONNECTION('FSMPCHHUBCAS01.FS.company.COM',25);
  5        lConnection := UTL_SMTP.OPEN_CONNECTION('10.32.16.54',25);
  6        DBMS_OUTPUT.PUT_LINE('Opened ok');
  7  
  8        UTL_SMTP.HELO(lConnection, 'OSSWKS2R2YQ1S');
  9        DBMS_OUTPUT.PUT_LINE('HELO ok');
 10  
 11        UTL_SMTP.MAIL(lConnection, 'ramkumar.n@fs.company.com');
 12        UTL_SMTP.RCPT(lConnection, 'ramkumar.n@fs.company.com');
 13        DBMS_OUTPUT.PUT_LINE('Addressing ok');
 14  end;
 15  /
declare
*
ERROR at line 1:
ORA-29278: SMTP transient error: 421 Service not available
ORA-06512: at "SYS.UTL_SMTP", line 20
ORA-06512: at "SYS.UTL_SMTP", line 96
ORA-06512: at "SYS.UTL_SMTP", line 138
ORA-06512: at line 5

SQL> BEGIN
  2  EXECUTE IMMEDIATE 'ALTER SESSION SET smtp_out_server = "10.32.16.54:25"';
  3  END;
  4  /

PL/SQL procedure successfully completed.

SQL> DECLARE
  2    --l_mailhost    VARCHAR2(64) := 'FSMPCHMBX01.FS.company.COM';
  3    l_mailhost    VARCHAR2(64) := '10.32.16.54';
  4    l_from        VARCHAR2(64) := 'ramkumar.n@fs.company.com';
  5    l_to          VARCHAR2(64) := 'ramkumar.n@fs.company.com';
  6    l_mail_conn   UTL_SMTP.connection;
  7  BEGIN
  8    l_mail_conn := UTL_SMTP.open_connection(l_mailhost, 25);
  9    UTL_SMTP.helo(l_mail_conn, l_mailhost);
 10    UTL_SMTP.mail(l_mail_conn, l_from);
 11    UTL_SMTP.rcpt(l_mail_conn, l_to);
 12    UTL_SMTP.data(l_mail_conn, 'Single string message.' || Chr(13))
 13    UTL_SMTP.quit(l_mail_conn);
 14  END;
 15  /
DECLARE
*
ERROR at line 1:
ORA-29278: SMTP transient error: 421 Service not available
ORA-06512: at "SYS.UTL_SMTP", line 20
ORA-06512: at "SYS.UTL_SMTP", line 96
ORA-06512: at "SYS.UTL_SMTP", line 138
ORA-06512: at line 8

create FUNCTION PING_host(p_HOST_NAME VARCHAR2, p_PORT NUMBER DEFAULT 1000) RETURN VARCHAR2
  IS
    tcpConnection  UTL_TCP.CONNECTION;  --TCP/IP connection to the server
    C_PING_OK           CONSTANT VARCHAR2(10)  := 'OK';
C_PING_ERROR        CONSTANT VARCHAR2(10)  := 'ERROR';
  BEGIN
    tcpConnection := UTL_TCP.open_connection(remote_host => p_HOST_NAME, remote_port => p_PORT);

    UTL_TCP.close_connection(tcpConnection);
    --Que raro...el host tiene abierto el puerto 1000...
    RETURN C_PING_OK||p_port;
  EXCEPTION
    WHEN UTL_TCP.NETWORK_ERROR THEN
      IF( UPPER(SQLERRM) LIKE '%HOST%' )THEN --Host inaccesible
        RETURN C_PING_ERROR;
      ELSIF(UPPER(SQLERRM) LIKE '%LISTENER%' )THEN

        RETURN C_PING_OK;
      ELSE--Mensaje SQLERRM desconocido: este es un error grave!
        RAISE;
      END IF;
  END PING_host;

SQL> set serverout on;
SQL> declare
  2    msg varchar2(100);
  3  begin
  4    msg := ping_host('10.32.16.54','25');
  5    dbms_output.put_line(msg);
  6  end;
  7  /
OK

PL/SQL procedure successfully completed.

SQL> create or replace FUNCTION PING_server(p_HOST_NAME VARCHAR2, p_PORT NUMBER DEFAULT 1000) RETURN
 VARCHAR2
  2    IS
  3      tcpConnection  UTL_TCP.CONNECTION;  --TCP/IP connection to the server
  4      C_PING_OK           CONSTANT VARCHAR2(10)  := 'OK';
  5  C_PING_ERROR        CONSTANT VARCHAR2(10)  := 'ERROR';
  6    BEGIN
  7      tcpConnection := UTL_TCP.open_connection(remote_host => p_HOST_NAME, remote_port => p_PORT)
;
  8  
  9      UTL_TCP.close_connection(tcpConnection);
 10      --Que raro...el host tiene abierto el puerto 1000...
 11      RETURN C_PING_OK||p_port;  
 12    END PING_server;
 13  
 14  /

Function created.

SQL> set serverout on;
SQL>      declare
  2        msg varchar2(100);
  3      begin
  4        msg := ping_server('10.32.16.54','25');
  5        dbms_output.put_line(msg);
  6      end;
  7      /
     declare
*
ERROR at line 1:
ORA-29260: network error: TNS:no listener
ORA-06512: at "SYS.UTL_TCP", line 28
ORA-06512: at "SYS.UTL_TCP", line 257
ORA-06512: at "PREMIAUAE.PING_SERVER", line 7
ORA-06512: at line 4

 sho parameter smtp_out_server