holstein-kiel.de

Checked 21 October 2026, 22:50 UTC · via 8.8.8.8
✗Problems found
18 passed 4 warnings 1 failed 3 info

SPF

pass

SPF record published

Found

Record
v=spf1 include:spf.protection.outlook.com ip4:84.200.65.156 include:tng.de a:mx4.eventim.de ~all
DNS lookups
3 of 10
Void lookups
0 of 2

Checks

  • ✓ No deprecated ptr mechanism #1
    No ptr mechanism found in SPF record.
  • ✓ 3 of 10 DNS lookups #2
    SPF record needs 3 DNS lookups (limit is 10).
  • ✓ Ends with ~all #3
    SPF record properly uses ~all to restrict unauthorized senders.
  • ✓ Record published #6
    SPF record exists for this domain.
  • ✓ Single record #16
    Exactly one SPF record is published.
  • ✓ Valid syntax #25
    All SPF mechanisms and modifiers are valid.
  • ✓ No void lookups #26
    All include/redirect targets exist.
  • ✓ No overly broad IP ranges #27
    All ip4/ip6 ranges are narrow enough.

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

Selectors: mail, selector1, selector2

Found

Selectors
mail, selector1, selector2
_domainkey
NOERROR
SelectorKeyFlags
mailRSA 2048 bits
selector1RSA 1024 bits
selector2RSA 1024 bits

Checks

  • ✓ Keys found: mail, selector1, selector2 #7
    DKIM keys found for this domain with selectors: mail, selector1, selector2
  • !
    1024-bit DKIM key
    1024-bit RSA keys are the minimum and are considered weak today: selector1 (1024 bits), selector2 (1024 bits). Rotate to a 2048-bit key.
    #23
  • ✓ No problematic flags #24
    No keys in test mode, revoked, or limited to SHA-1.

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
10holsteinkiel-de02b.mail.protection.outlook.comA 52.101.181.153 A 52.101.185.114 A 52.101.68.39 A 52.101.103.162 AAAA 2a01:111:f403:ca48::a AAAA 2a01:111:f403:ca21::c AAAA 2a01:111:f403:ca09::24 AAAA 2a01:111:f403:ca21::8mail-wa4pr04cu00101.inbound.protection.outlook.com ✓ mail-zrxpr04cu00102.inbound.protection.outlook.com ✓ mail-db7pr03cu00607.inbound.protection.outlook.com ✓ mail-miypr03cu00202.inbound.protection.outlook.com ✓ mail-miypr02cu00202.inbound.protection.outlook.com ✓ mail-matpr04cu00204.inbound.protection.outlook.com ✓ mail-am6pr02cu00204.inbound.protection.outlook.com ✓ mail-matpr04cu00100.inbound.protection.outlook.com ✓

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 8 MX addresss have a PTR record that resolves back to them.

TLS

warn

no MTA-STS · no TLS-RPT · DANE on 0 of 1 MX hosts

Found

DANE (TLSA records)

MX hostTLSADNSSEC
holsteinkiel-de02b.mail.protection.outlook.comnone-

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
  • i
    Not configured
    TLS-RPT lets senders report TLS delivery problems to you. It is most useful together with MTA-STS or DANE.
    #35
  • i
    Not used
    No MX host publishes TLSA records. DANE lets senders verify your mail server's certificate through DNSSEC; it requires DNSSEC on the MX host's zone.
    #36

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