Tell what? There are databases that are used to basically check the emails you provide for privacy, this means the list you provided is checked against the entire database of public emails (antipublic) and the result is shown on the screen leaving the full private (non found on the database) hits unveiled.
In this case, the valid rate and the private rate of your combos is really low. This leads me to understand the combo lists you are selling are not good enough quality to be sold on nulled.
Send me this database site or program so I could test combos