In your policy it is looking for attribute id called "http://wso2.org/claims/emailaddress" And it is not available in your request.
Please check your request, As following, You are sending the email address with different attribute id.
Also, If you wish to send only the user name using the XACML request and you want to retrieve the email using PIP attribute finder. You can use "http://wso2.org/claims/emailaddress" attribute id in policy. This is the attribute id to retrieve policies from WSO2 Identity Server user store. You can create a user and set the email address as "utsav@domain.com" using user profiles. Then once you send a request with only the user name PIP would retrieve the corresponding attribute value from user store.
<Attributes Category="urn:oasis:names:tc:xacml:1.0:subject-category:access-subject"> <Attribute AttributeId="urn:oasis:names:tc:xacml:1.0:subject:subject-id" IncludeInResult="false"> <AttributeValue DataType="http://www.w3.org/2001/XMLSchema#string">utsav@domain.com</AttributeValue> </Attribute> </Attributes>