Unsubscribe link from a resource in the local network?

Question

CRM

Hello, how to safely implement the ability to unsubscribe from mailing lists to company customers with an internal corporate CRM, provided that you don’t want to expose the CRM outside, it’s clear that you will have to publish it partially within the function-dependent directories on the web server, but how to do it as safely as possible.
The link looks like domain?entryPoint=removeme&identifier=xxxxx
Sorry for the inaccuracy, the domain on which crm can be accessed or part of it is registered.

Answer 1

Write a simple service on anything and bring it to the network, and this service will knock on the LAN on the CPM when a request arrives, or even easier, it will process it.

Answer 2

make a proxy server using nginx somewhere on a different domain