Email clients invalidating email confirmation links


I’ve heard that when an app sends an email asking to confirm your email address, that some email clients ping the link in the background to check if it’s legit and in doing so confirm the email address for the user. The problem is when the user clicks on the link in the email, because the client has automatically done it in the background, they get an error.

Does anyone have any further details on this? Keen to understand the scale of it and best approaches for dealing with it.