The term data hygiene refers to checking database records for accuracy and removing all erroneous entries. The person performing the task is referred to as a data hygienist. A number of data hygiene tools and services exist.
Perhaps the most common data hygiene procedure is 'deduping' (removing duplicate records). All modern CRM software, like Bitrix24, is capable of performing the task automatically. It's also possible to create automatic workflows, requiring account managers to periodically check that all contact information for their accounts is still accurate.
If you are looking for free CRM software with over 20 sales and marketing tools, consider Bitrix24.