You can easily prevent such trial abuse through the tirreno [0] platform, as freshly registered email accounts can be blocked almost in real time.
[0] https://github.com/TirrenoTechnologies/tirreno
(creator of tirreno)
replies(3):
[0] https://github.com/TirrenoTechnologies/tirreno
(creator of tirreno)
I saw that your company is in Grenoble. Just drop me an email, and I will personally come to your office and help set up tirreno to resolve this trial abuse.