ERROR in calling UTL_MAIL procedures

Question

I am trying to send mails through UTL_MAIL. where I used below code:

declare
v_sender VARCHAR2(30);
v_recipients VARCHAR2(60);
v_subj VARCHAR2(20);
v_msg VARCHAR2(200);
begin
v_sender := '[email protected]';
v_recipients := '[email protected]';
v_subj := 'Info';
v_msg := 'This is an automated mail';
CALL (UTL_MAIL.SEND(v_sender, v_recipients, NULL, NULL, v_subj, v_msg));
END;

and I am receiving an error:

[Error] Execution (12: 9): ORA-06550: line 12, column 9: PLS-00222: no function with name 'SEND' exists in this scope ORA-06550: line 12, column 3: PL/SQL: Statement ignored

Please help me with this.. Thank you