DNS resolver can run for longer than the given timeout

It's very hard to reproduce, we found the problem because we have a 60s timeout for our web server that we kept busting, even with email-validator's default 15s timeout.

Disabling check_availability solved our problem.

The problem

The problem lies within:

response = dns_resolver.resolve(domain, "MX")

( https://github.com/JoshData/python-email-validator/blob/main/email_validator/deliverability.py#L40 )

While debugging, what I can see is that the resolver goes through a loop, and only checks the timeout between calls. It also does some time.sleep()
That means that if a call or a sleep is longer than the timeout, it doesn't get interrupted and can thus run for longer

The solution

Using signal, we could interrupt the process. See https://stackoverflow.com/a/494273

This package does it: https://github.com/pnpnpn/timeout-decorator

I'll try implementing the stackoverflow suggestion on my end and write back with news

Commencez dans deliverability.py, au niveau de l’appel dns_resolver.resolve(domain, "MX"), et suivez la façon dont le délai d’expiration configuré est transmis lorsque check_availability est activé. Reproduisez ou examinez la boucle du resolver et le comportement de sleep décrits dans l’issue. Le travail est terminé lorsque la résolution DNS ne s’exécute pas au-delà du délai indiqué, tout en préservant le comportement existant de deliverability.