How can I create random emails for each customer? [on hold]

How can I create random emails for each customer so external companies can send them mail without knowing the real address?

I need this because I have to share some email address with external companies for every customer that uses a service of the company. Because of GPDR I cannot just share the real email address of the customer and have to use a randomly generated alias. This should be the same as Amazon does when they transmit email addresses of their customers to 3rd party sellers. Of course the external company will send a few emails to this random address and they should be redirected to the real email, but the random address will not send any email (only an alias to receive them).

What kind of infrastructure and logic will I need to do something like this? Which services may already be able to do this for me?

Thanks for helping!