Hits to spam traps typically occur due to list acquisition practices. If email addresses are not validated during the sign-up process, or if confirmed/double opt in processes are not used, then spam trap addresses can be intentionally or inadvertently added to a list. Email append or list rental / purchase is another reason that you may hit many traps. Often these sources of data may not have the permission level they indicate, or they may be severely outdated. It is also possible to have inactive addresses on your list for so long and to ignore bounces such that email addresses that were once good are now operated as “recycled” or “grey” spam traps (rather than pristine).