Managing personal Outlook.com account settings, security, and privacy
Hi RichardKav,
I understand that you would like to prevent bots from signing up under your website. I know how inconvenient this must be on your end. Don't worry, let us assist you with this.
For this issue, what we can suggest is that you increase the security level of your website. One example is including CAPTCHA when signing up for your website for an email address to make sure the one signing up is human.
Please let us know if you have additional questions.
Thanks!