Is a8.keio.jp valid?

a8.keio.jp 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": "a8.keio.jp",
    "base_domain": "keio.jp",
    "text": "Domain does not accept email",
    "reason": "null_mx",
    "risk": 15,
    "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": true,
    "is_parked": false,
    "is_role_based_email": false,
    "mx_host": "mailgate3-2.keio.jp",
    "mx_ip": "131.113.132.11",
    "mx_info": "Domain declares it accepts no mail (RFC 7505 null MX).",
    "mx_fallback": false,
    "mx_hosts": [
        "mailgate3-2.keio.jp",
        "mailgate3-1.keio.jp"
    ],
    "mx_ips": [
        "131.113.132.11",
        "131.113.132.10"
    ],
    "mx_priorities": {
        "mailgate3-1.keio.jp": 10,
        "mailgate3-2.keio.jp": 10
    },
    "email_provider": null,
    "disposable_provider": null,
    "possible_typo": [],
    "domain_age_days": null,
    "domain_created_at": null,
    "block_status_changed_at": "2026-09-12T13:46:34+00:00"
}