The vwPROSPECT_LISTS_Emails view combines the Contacts, Prospects, Leads and Users into a single result set.  In order to be included in the list the EMAIL1 of each of those records must not be NULL.  Also, the EMAIL_OPT_OUT nost not be 1 and INVALID_EMAIL must not be 1.  If your list does not include the one contact or the one user as expected, then it is likely that the EMAIL1 of those records is null.