Laravel - How to Stop Spam registers

So I have a website, I added e-mail verification system. But I noticed that, some people can fake mails and spam again and again. I wonder how I can stop spam registers to my website? I want to just allow few emails to be able to register like gmail, hotmail etc.

I heard that regex could work in Validation part of register but I dont know how I should syntax exactly. Any ideas how I can solve this problem?

I mean to stop people who can register again and again with fake emails. I dont mean bots..

via Chebli Mohamed