@Param 어노테이션으로 명시해주어야함
public void registCustMail(@Param("custCode") String custCode, @Param("custEmailId") String custEmailId);
<update id="registCustMail"parameterType="com.cs.api.model.CsCustMailInfo">
UPDATE AMAILCSNEW.dbo.CUSTOMERINFO
SET CUST_EMAIL_ID=#{custEmailId}
WHERE CUST_CODE=#{custCode}
</update>