Resolved: Getting additional e_id even after joining conditions are satisfied in SELECT query

CREATE TABLE test_tab (
    e_id       NUMBER(10),
    sys_name   VARCHAR2(20),
    ref_id     NUMBER(10),
    sys_other  VARCHAR2(20)
);

INSERT INTO test_tab VALUES(805,'SRC',NULL,'Email');
INSERT INTO test_tab VALUES(805,'SRC',NULL,'Test');
INSERT INTO test_tab VALUES(805,'TGT',NULL,null);
INSERT INTO test_tab VALUES(805,'TGT',128,'Email');
INSERT INTO test_tab VALUES(6122,'SRC',NULL,'Email');
INSERT INTO test_tab VALUES(6122,'TGT',NULL,'Email');
INSERT INTO test_tab VALUES(122,'SRC',128,null);
INSERT INTO test_tab VALUES(122,'TGT',128,null);

COMMIT;

SELECT e_id,ref_id,sys_other
FROM test_tab
WHERE ref_id IS NOT NULL
  AND (sys_other = 'Email' OR sys_other IS NULL)
GROUP BY e_id,ref_id,sys_other;

+------+--------+-----------+
| E_ID | REF_ID | SYS_OTHER |
+------+--------+-----------+
|  122 |    128 | null      |
+------+--------+-----------+

SELECT e_id,
       MAX(ref_id)    AS ref_id,
       MAX(sys_other) AS sys_other
FROM   test_tab
GROUP BY e_id
HAVING COUNT(ref_id) > 0
AND    COUNT(CASE WHEN sys_other <> 'Email' THEN 1 END) = 0;