st-ab.nl

Checked 22 October 2026, 16:11 UTC · via 8.8.8.8
✗Problems found
9 passed 5 warnings 2 failed 1 info

SPF

fail

No SPF record found

Checks

  • ✗
    No SPF record
    No SPF record was found for this domain. SPF is important for preventing email spoofing. Add an SPF record to specify which servers are authorized to send email for your domain.
    #6

DMARC

fail

No DMARC record found

Checks

  • ✗
    No DMARC record
    No DMARC record was found for this domain. DMARC is essential for preventing email spoofing. Add a DMARC record with p=reject or at least p=quarantine.
    #5

DKIM

warn

No keys found under the checked selectors

Found

Selectors
None found
_domainkey
NOERROR

Checks

  • !
    No key under common selectors
    The _domainkey name exists but no DKIM key was found under the common selectors. Selectors are provider-specific; check yours with -selector.
    #7

DNSSEC

warn

Not signed

Found

DNSKEY records
No (0)
DS at parent
No

Checks

  • !
    Not enabled
    DNSSEC is not enabled for this domain. Consider enabling DNSSEC to protect against DNS spoofing attacks.
    #8

MX

warn

1 mail server

Found

PriorityHostRecordsReverse DNS
10antispamcluster.protagonist.nlA 185.214.148.180 A 217.18.77.180 A 217.18.64.180 A 185.214.148.80 A 185.214.148.250 AAAA 2a00:19c0:a064:180::1 AAAA 2a00:19c0:d148::250 AAAA 2a00:19c0:d148::180 AAAA 2a00:19c0:b077:180::1 AAAA 2a00:19c0:d148::80antispam7.protagonist.nl ✓ antispam9.protagonist.nl ✓ antispam8.protagonist.nl ✓ antispam6.protagonist.nl ✓ antispam1.protagonist.nl ✓ antispam8.protagonist.nl ✓ antispam1.protagonist.nl ✓ antispam7.protagonist.nl ✓ antispam9.protagonist.nl ✓ antispam6.protagonist.nl ✓

Checks

  • ✓ 1 MX record #9
    Found 1 MX records for this domain.
  • ✓ All hosts resolve #10
    All MX records resolve to valid IP addresses.
  • ✓ All hosts have IPv6 #11
    All MX records resolve to IPv6 addresses.
  • !
    Single MX host, no backup
    Only one MX record found. For better email reliability, consider adding at least one backup MX server.
    #12
  • ✓ At most 5 MX records #13
    Found 1 MX records, which is within the recommended range (1-5).
  • ✓ No localhost targets #14
    No MX records pointing to localhost found.
  • ✓ No private IP addresses #15
    No MX records resolving to private IP addresses found.
  • ✓ No CNAME targets #22
    No MX records point to a CNAME.
  • ✓ Reverse DNS confirmed #30
    All 10 MX addresss have a PTR record that resolves back to them.

TLS

warn

no MTA-STS · no TLS-RPT · DANE on 1 of 1 MX hosts

Found

DANE (TLSA records)

MX hostTLSADNSSEC
antispamcluster.protagonist.nl3 1 1 d6c4c7e685c146cf…Yes

Checks

  • !
    Not configured
    MTA-STS is not configured, so other mail servers fall back to unencrypted delivery when TLS fails or is stripped by an attacker. Publish a _mta-sts TXT record and a policy at https://mta-sts.<domain>/.well-known/mta-sts.txt.
    #32
  • !
    Not configured
    MTA-STS or DANE is used without TLS-RPT, so you get no reports when senders fail to deliver because of TLS problems. Publish _smtp._tls TXT "v=TLSRPTv1; rua=mailto:...".
    #35
  • ✓ DANE on all MX hosts #36
    All 1 MX host publish DNSSEC-validated TLSA records.

BIMI

info

No BIMI record

Checks

  • i
    Not configured
    BIMI shows your logo next to your mail in supporting mail clients. It requires DMARC enforcement.
    #38