When a user register to my web application I send an email to verify his inbox. In the email there are a link to a resource like this:
GET /verify/{token}
Aren't you overthinking REST? With e-mail verification you want the user to be able to simply click the link from whatever mail user agent he is using, so you'll end up with a simple GET on the server (presented as a hyperlink to the user) with the token either in the path or as part of the query string:
GET http://example.com/verify-email/TOKEN
GET http://example.com/verify-email?token=TOKEN
Either is fine for this use case. It is not really a resource you are getting or creating; just a trigger for some process on the backend.
Why do you think this would run afoul of good design?