denic.de

Checked 21 October 2026, 22:13 UTC · via 8.8.8.8
!Passed with warnings
32 passed 2 warnings 0 failed

SPF

pass

SPF record published

Found

Record
v=spf1 a mx ip4:81.91.161.53 ip4:81.91.161.54 ip6:2a02:568:102:211::1:16 ip6:2a02:568:102:211::1:17 include:mailbox.org ~all
DNS lookups
4 of 10
Void lookups
0 of 2

Checks

  • ✓ No deprecated ptr mechanism #1
    No ptr mechanism found in SPF record.
  • ✓ 4 of 10 DNS lookups #2
    SPF record needs 4 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

pass

p=reject (_dmarc.denic.de)

Found

Record
v=DMARC1; p=reject; rua=mailto:dmarcrep@denic.de; rf=afrf; sp=reject; fo=0; ri=86400; adkim=r; aspf=r; pct=100
Found at
_dmarc.denic.de
TagValueMeaning
vDMARC1Version
prejectPolicy
sprejectSubdomain policy
pct100Percentage of mail the policy applies to
ruamailto:dmarcrep@denic.deAggregate report addresses
adkimrDKIM alignment (r = relaxed, s = strict)
aspfrSPF alignment (r = relaxed, s = strict)
fo0Failure reporting options
rfafrfFailure report format
ri86400Report interval (seconds)

Checks

  • ✓ Policy: reject #4
    DMARC policy is set to 'reject', which provides the strongest protection against email spoofing.
  • ✓ Record published #5
    DMARC record exists for this domain.
  • ✓ Valid syntax #17
    DMARC record syntax is valid.
  • ✓ Applies to 100% of mail #18
    DMARC policy applies to all failing mail.
  • ✓ Aggregate reports enabled #19
    Aggregate reports are sent to: mailto:dmarcrep@denic.de
  • ✓ Subdomain policy: reject #20
    Subdomains are covered by policy 'reject'.
  • ✓ Report addresses in own domain #29
    All report addresses are in your own organizational domain.

DKIM

pass

Selectors: mail

Found

Selectors
mail
_domainkey
NOERROR
SelectorKeyFlags
mailRSA 2048 bits

Checks

  • ✓ Keys found: mail #7
    DKIM keys found for this domain with selectors: mail
  • ✓ Strong keys #23
    DKIM keys are strong enough: mail: RSA 2048 bits.
  • ✓ No problematic flags #24
    No keys in test mode, revoked, or limited to SHA-1.

DNSSEC

pass

Signed, DS published at parent

Found

DNSKEY records
Yes (2)
DS at parent
Yes
Algorithms
RSASHA256 (8)
Key tags
29355, 26155
Signatures valid until
4 November 2026, 12:44 UTC

Checks

  • ✓ Signed, DS published at parent #8
    DNSSEC is enabled for this domain (DNSKEY and DS present), providing additional security for DNS lookups.
  • ✓ Signatures valid until 2026-11-04 #21
    DNSKEY signatures are valid until 2026-11-04T12:44:39Z.

MX

pass

4 mail servers

Found

PriorityHostRecordsReverse DNS
10mxext1.mailbox.orgA 80.241.60.212 AAAA 2001:67c:2050:104:0:1:25:1mx1.mailbox.org ✓ mx1.mailbox.org ✓
10mxext2.mailbox.orgA 80.241.60.215 AAAA 2001:67c:2050:104:0:2:25:1mx2.mailbox.org ✓ mx2.mailbox.org ✓
10mxext3.mailbox.orgA 80.241.60.216 AAAA 2001:67c:2050:104:0:3:25:1mx3.mailbox.org ✓ mx3.mailbox.org ✓
10mxext4.mailbox.orgA 80.241.60.217 AAAA 2001:67c:2050:104:0:4:25:1mx4.mailbox.org ✓ mx4.mailbox.org ✓

Checks

  • ✓ 4 MX records #9
    Found 4 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.
  • ✓ Redundant MX hosts #12
    Found 4 MX records, which provides redundancy for email delivery.
  • ✓ At most 5 MX records #13
    Found 4 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 4 of 4 MX hosts

Found

DANE (TLSA records)

MX hostTLSADNSSEC
mxext1.mailbox.org3 1 1 4758af6f02dfb5dc… 3 1 1 996ad31d65e03f03… 3 1 1 e41cc7633029afdb…Yes
mxext2.mailbox.org3 1 1 4758af6f02dfb5dc… 3 1 1 e41cc7633029afdb… 3 1 1 996ad31d65e03f03…Yes
mxext3.mailbox.org3 1 1 4758af6f02dfb5dc… 3 1 1 996ad31d65e03f03… 3 1 1 e41cc7633029afdb…Yes
mxext4.mailbox.org3 1 1 4758af6f02dfb5dc… 3 1 1 996ad31d65e03f03… 3 1 1 e41cc7633029afdb…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 4 MX hosts publish DNSSEC-validated TLSA records.

BIMI

pass

https://www.denic.de/fileadmin/Logo/Denic_de-Signet_RGB-BIMI-v2.svg

Found

Record
v=BIMI1; l=https://www.denic.de/fileadmin/Logo/Denic_de-Signet_RGB-BIMI-v2.svg; a=https://www.denic.de/fileadmin/Logo/Denic_de-VMC.pem
Found at
default._bimi.denic.de
Logo
https://www.denic.de/fileadmin/Logo/Denic_de-Signet_RGB-BIMI-v2.svg
Certificate
https://www.denic.de/fileadmin/Logo/Denic_de-VMC.pem

Checks

  • ✓ Logo and certificate published #38
    BIMI logo: https://www.denic.de/fileadmin/Logo/Denic_de-Signet_RGB-BIMI-v2.svg; certificate: https://www.denic.de/fileadmin/Logo/Denic_de-VMC.pem
  • ✓ DMARC meets BIMI requirements #39
    DMARC is enforced on all mail, as BIMI requires.