How to clean email list without a need to upload an email list every time?

If you don't want to spend time and developer resources on an API, connect your email service provider to mailfloss. You only have to do this once and from that point on your emails will automatically stay clean.

Email Checker offer a batch API that you can easily integrate, which will allow you to automate the sending and retrieving of files for verification.

You can sign up for a free account and test the solution here: login.emailchecker.com

Also if you enter CHECKER10 at checkout, you will get 10% discount off your order.

You can use DeBounce email validation API or it's email verification integration tool to validate your lists without uploading them manually.

MailboxValidator has API plans which you can use easily.

https://www.mailboxvalidator.com/api-single-validation

We also have ready made integrations if you are using some of the major email service providers like MailChimp, etc.

https://www.mailboxvalidator.com/integrations

There are few email verification services like ZeroBounce that offers Bulk email validation through API, which eliminates the need of manual process.