...Minor versions bumps will go via minor versions of this library (i.e: PHP7.3 -> v3.x+1). Major versions will go with major versions of the library. EmailValidatorrequires you to decide which (or combination of them) validation/s strategy/ies you'd like to follow for each validation. Note that warnings are deviations from the RFC that in a broader interpretation are acceptded. It's easy to extend! You just need to implement EmailValidation and you can use your own validation.