The WebCargo Email Check & Webform API (also known as Email Check API) allows you to deeply probe any email address. This REST API checks emails are against their constantly updated list of disposable email providers so you are protected from bounces and fake accounts. The API check your emails format/syntax, RFC compliance, MX-records (SMTP/IMAP), typos, account type (Free / Paid) and if it is a disposable address to make sure your emails don't bounce. WebCargo has a strict "no store" policy with the email addresses you validate.
WebCargo also allows you to upload a CSV to their bulk checker tool to process the query immediately.