There are mainly three ways of keeping an email list in a healthy state as below.
Real-time email verification through API - Real-time email verification verifies an email list at the point when email is entered in sign-up or subscription forms. Real-time email verification plays a great role in keeping invalid emails away from your email list.
Batch email verification - Bulk email validation is cleaning an entire email list at once. There are many email list cleaning services that do the email cleansing with ease. An email list can be verified in three simple steps i.e, Sign-up, Upload your email list, retrieve a clean email list.
Batch email verification through API - Bulk email validation through API is done programmatically by calling an API, it eliminates the process of uploading and downloading the email list manually.