mainz.de

Checked 21 October 2026, 23:21 UTC · via 8.8.8.8
✗Problems found
18 passed 2 warnings 2 failed 3 info

SPF

pass

SPF record published

Found

Record
v=spf1 ip4:83.243.48.64/26 ~all
DNS lookups
0 of 10
Void lookups
0 of 2

Checks

  • ✓ No deprecated ptr mechanism #1
    No ptr mechanism found in SPF record.
  • ✓ 0 of 10 DNS lookups #2
    SPF record needs 0 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

fail

No keys found under the checked selectors

Found

Selectors
None found
_domainkey
NXDOMAIN

Checks

  • ✗
    No DKIM keys published
    _domainkey.mainz.de does not exist (NXDOMAIN), so no DKIM keys are published. DKIM helps prevent email spoofing. Configure DKIM with your email service provider.
    #7

DNSSEC

pass

Signed, DS published at parent

Found

DNSKEY records
Yes (2)
DS at parent
Yes
Algorithms
ECDSAP256SHA256 (13)
Key tags
55652, 54152
Signatures valid until
24 December 2026, 10:45 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 2026-12-24 #21
    DNSKEY signatures are valid until 2026-12-24T10:45:00Z.

MX

warn

4 mail servers

Found

PriorityHostRecordsReverse DNS
10mailmx0001.rlp.deA 83.243.48.71mailmx0001.rlp.de ✓
10mailmx0002.rlp.deA 83.243.48.72mailmx0002.rlp.de ✓
10mailmx0003.rlp.deA 83.243.48.101mailmx0003.rlp.de ✓
10mailmx0004.rlp.deA 83.243.48.74mailmx0004.rlp.de ✓

Checks

  • ✓ 4 MX records #9
    Found 4 MX records for this domain.
  • ✓ All hosts resolve #10
    All MX records resolve to valid IP addresses.
  • !
    Hosts without IPv6
    The following MX hosts could not be resolved to IPv6 addresses: mailmx0001.rlp.de, mailmx0002.rlp.de, mailmx0003.rlp.de, mailmx0004.rlp.de
    #11
  • ✓ 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 4 MX addresss have a PTR record that resolves back to them.

TLS

warn

no MTA-STS · no TLS-RPT · DANE on 0 of 4 MX hosts

Found

DANE (TLSA records)

MX hostTLSADNSSEC
mailmx0001.rlp.denone-
mailmx0002.rlp.denone-
mailmx0003.rlp.denone-
mailmx0004.rlp.denone-

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