Hello @JeanE73 ,
It looks like those bot sign-ups are coming from a single embedded join-my-mailing-list (JMML) source. I'd recommend turning off / removing that form, and switching over to a better protected form like:
an Inline form (coded)
a Pop-up form (coded)
a Flyout form (coded)
a Banner form (coded)
a Sign-up Landing Page (linked)
I'd also advise setting your account up for Confirm Opt-In, as it helps to mitigate these kinds of mass bot sign-ups by requiring the tentative contact to explicitly clicking the link in the email our system sends to explicitly confirm the sign-up.
If you're having trouble finding the embedded JMML that's being used by the bots, I'd advise calling our general support so they can confirm permissions live with you, and work with our Tier 2 team to locate and break the form.
See also:
Installing coded forms onto compatible site builders
Finding and sharing lead gen landing page URLs
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