Is fu.rr.nu valid?

fu.rr.nu is a domain that should be blocked from sign-ups or registrations. Based on our analysis, you should block this domain. If a user is trying to sign-up using an e-mail on this domain, it's likely that it's a malicious or fraudulent attempt.

Raw API JSON response:

{
    "valid": true,
    "block": true,
    "domain": "fu.rr.nu",
    "base_domain": "rr.nu",
    "text": "Highly suspicious",
    "reason": "Anomalies detected",
    "risk": 95,
    "is_disposable": false,
    "is_email_forwarder": false,
    "is_public_free": false,
    "is_public_premium": false,
    "is_business_provider": false,
    "is_isp_email": false,
    "is_email_api": false,
    "is_web_hosting_email": false,
    "is_self_hosted": false,
    "is_parked": false,
    "is_role_based_email": false,
    "mx_host": "fu.rr.nu",
    "mx_ip": "23.139.248.91",
    "mx_info": "No MX-pointer in DNS record. Using domain: fu.rr.nu",
    "mx_fallback": true,
    "mx_hosts": [
        "fu.rr.nu"
    ],
    "mx_ips": [
        "23.139.248.91"
    ],
    "mx_priorities": [],
    "email_provider": null,
    "disposable_provider": null,
    "possible_typo": [],
    "domain_age_days": null,
    "domain_created_at": null,
    "block_status_changed_at": "2025-05-05T12:25:34+00:00"
}