SCOTT@orcl12c> -- table containing emails:
SCOTT@orcl12c> CREATE TABLE customer_emails
  2    (emailid     NUMBER,
  3  	email	    VARCHAR2(4000))
  4  /

Table created.

SCOTT@orcl12c> INSERT ALL
  2  INTO customer_emails VALUES
  3    (1, 'I have a minor problem with Oracle 12c in the USA.')
  4  INTO customer_emails VALUES
  5    (2, 'I am in the UK and my Microsoft smartscreen filter is causing a major problem.')
  6  SELECT * FROM DUAL
  7  /

2 rows created.

SCOTT@orcl12c> -- table of categories to load email data into:
SCOTT@orcl12c> CREATE TABLE email_categories
  2    (emailid     NUMBER,
  3  	product     VARCHAR2(15),
  4  	country     VARCHAR2(15),
  5  	version     VARCHAR2(15),
  6  	severity    VARCHAR2(15))
  7  /

Table created.

SCOTT@orcl12c> -- policy and rules you create to determine what data goes into what categories:
SCOTT@orcl12c> BEGIN
  2    CTX_ENTITY.CREATE_EXTRACT_POLICY ('email_pol');
  3    CTX_ENTITY.ADD_EXTRACT_RULE
  4  	 ('email_pol',
  5  	  1,
  6  	  '<rule>
  7  	     <expression>(Oracle|Microsoft)</expression>
  8  	     <type refid="1">product</type>
  9  	   </rule>');
 10    CTX_ENTITY.ADD_EXTRACT_RULE
 11  	 ('email_pol',
 12  	  2,
 13  	  '<rule>
 14  	     <expression>(UK|USA)</expression>
 15  	     <type refid="1">country</type>
 16  	   </rule>');
 17    CTX_ENTITY.ADD_EXTRACT_RULE
 18  	 ('email_pol',
 19  	  3,
 20  	  '<rule>
 21  	     <expression>(11g|12c)</expression>
 22  	     <type refid="1">xversion</type>
 23  	   </rule>');
 24    CTX_ENTITY.ADD_EXTRACT_RULE
 25  	 ('email_pol',
 26  	  4,
 27  	  '<rule>
 28  	     <expression>(major|minor)</expression>
 29  	     <type refid="1">xseverity</type>
 30  	   </rule>');
 31    CTX_ENTITY.COMPILE ('email_pol');
 32  END;
 33  /

PL/SQL procedure successfully completed.

SCOTT@orcl12c> -- parse email data and insert into categories:
SCOTT@orcl12c> DECLARE
  2    v_entities  CLOB;
  3  BEGIN
  4    FOR r IN (SELECT * FROM customer_emails) LOOP
  5  	 CTX_ENTITY.EXTRACT ('email_pol', r.email, NULL, v_entities);
  6  	 INSERT INTO email_categories (emailid, product, country, version, severity)
  7  	 SELECT r.emailid,
  8  		MAX (DECODE (foo.type, 'product',   foo.text)),
  9  		MAX (DECODE (foo.type, 'country',   foo.text)),
 10  		MAX (DECODE (foo.type, 'xversion',  foo.text)),
 11  		MAX (DECODE (foo.type, 'xseverity', foo.text))
 12  	 FROM	XMLTABLE
 13  		  ('/entities/entity'
 14  		   PASSING XMLTYPE (v_entities)
 15  		   COLUMNS
 16  		     offset  NUMBER	   PATH '@offset',
 17  		     lngth   NUMBER	   PATH '@length',
 18  		     text    VARCHAR2(50)  PATH 'text/text()',
 19  		     type    VARCHAR2(50)  PATH 'type/text()',
 20  		     source  VARCHAR2(50)  PATH '@source') AS foo
 21  	 GROUP	BY r.emailid;
 22    END LOOP;
 23  END;
 24  /

PL/SQL procedure successfully completed.

SCOTT@orcl12c> -- results:
SCOTT@orcl12c> SELECT * FROM email_categories
  2  /

   EMAILID PRODUCT         COUNTRY         VERSION         SEVERITY
---------- --------------- --------------- --------------- ---------------
         1 Oracle          USA             12c             minor
         2 Microsoft       UK                              major

2 rows selected.