It’s not going to work the same.
One of the go-to methods for contacting many clients is mass-email.
Here we use Campaign Monitor, but there are many others including the venerable MailChimp.
All of these systems allow you to track whether someone has opened their email, where they were when you opened the email and many other features. (Whether you do track these things should be reflected in your privacy policy and whether a client allows you to track these things.)
These things are all going to break with the way Apple is changing the way it connects to email services.
This is to give your clients (and you) more privacy. So, it is a good thing.
It will impact your mass emails.
Here is a great video from Campaign Monitor, detailing the changes.
https://www.campaignmonitor.com/resources/webinars/navigating-an-evolving-privacy-environment/view/
