ora-24247 network access is denied by access control list ACL

--1. Create an Access control List (ACL),
BEGIN

Dbms_network_acl_admin. Create_acl (
Acl='Email_server_permissions.xml',
Description='enables network permissions for the e-mail server',
Principal='NC633',--This is the user who will be working in the future
Is_grant=TRUE,
Privilege='Connect');
END;
/

--2. Associate this ACL with the mail server,
BEGIN
Dbms_network_acl_admin.assign_acl (
Cc.= 'Email_server_permissions.xml',
Host='10.10.0.200',--SMTP Server address
Lower_port= -,
Upper_port= -);
COMMIT;
END;
/

----Query
SELECTHost, Lower_port, Upper_port, ACL fromDba_network_acls;


SELECTAcl
Principal
Privilege
Is_grant,
To_char (Start_date,'dd-mon-yyyy') asStart_date,
To_char (End_date,'dd-mon-yyyy') asEnd_date
fromDba_network_acl_privileges;

ora-24247 network access is denied by access control list ACL