Why can't I get the data when I used hbase CompareOp.valueOf('EQUAL') in scan FILTER to query the rows?

Question

I want to query the rows with hbase CompareOp.valueOf('EQUAL') in scan FILTER like this, but I can't get the data, and I'm sure there are data matching condition in the hbase.

import org.apache.hadoop.hbase.filter.CompareFilter
import org.apache.hadoop.hbase.filter.SingleColumnValueFilter
import org.apache.hadoop.hbase.filter.SubstringComparator
import org.apache.hadoop.hbase.util.Bytes

scan 'HBASE_TABLE',
    {COLUMNS => ['INFO:EMAILTYPE'],
    FILTER => SingleColumnValueFilter.new(Bytes.toBytes('EMAILTYPE'),
              CompareOp.valueOf('EQUAL'),Bytes.toBytes('gmail.com'))}

Is it because 'gmail.com' contains a dot/point?