guj.de

Checked 21 October 2026, 22:41 UTC · via 8.8.8.8
✗Problems found
21 passed 5 warnings 1 failed 3 info

SPF

pass

SPF record published

Found

Record
v=spf1 ip4:194.12.192.0/19 ip4:194.232.25.221 ip4:193.7.250.235 ip4:165.72.200.0/24 ip4:149.96.13.2 ip4:149.96.14.2 ip4:151.106.144.150 ip4:84.17.184.0/24 ip4:80.252.110.2 ip4:46.20.32.254 ip4:13.69.143.169 a:mout.kundenserver.de include:_spf.zimpel.de include:amazonses.com a:sul.rtl.de a:sulis.rtl.de include:spf.protection.outlook.com include:_spf.salesforce.com ~all
DNS lookups
8 of 10
Void lookups
0 of 2

Checks

  • ✓ No deprecated ptr mechanism #1
    No ptr mechanism found in SPF record.
  • ✓ 8 of 10 DNS lookups #2
    SPF record needs 8 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

p=none (_dmarc.guj.de)

Found

Record
v=DMARC1;p=none;adkim=r;aspf=r;pct=100;ruf=mailto:dmarc@guj.de;fo=1;
Found at
_dmarc.guj.de
TagValueMeaning
vDMARC1Version
pnonePolicy
pct100Percentage of mail the policy applies to
rufmailto:dmarc@guj.deFailure report addresses
adkimrDKIM alignment (r = relaxed, s = strict)
aspfrSPF alignment (r = relaxed, s = strict)
fo1Failure reporting options

Checks

  • ✗
    Policy: none (monitoring only)
    DMARC policy is set to 'none', which only monitors but doesn't protect against spoofing. Consider upgrading to 'quarantine' or ideally 'reject'.
    #4
  • ✓ Record published #5
    DMARC record exists for this domain.
  • ✓ Valid syntax #17
    DMARC record syntax is valid.
  • !
    No aggregate reports (rua)
    DMARC record has no rua tag, so you receive no aggregate reports about who sends mail as your domain. Add rua=mailto:...
    #19
  • ✓ Report addresses in own domain #29
    All report addresses are in your own organizational domain.

DKIM

warn

Selectors: s1, s2

Found

Selectors
s1, s2
_domainkey
NOERROR
SelectorKeyFlags
s1RSA 2048 bits
s2RSA 1024 bits

Checks

  • ✓ Keys found: s1, s2 #7
    DKIM keys found for this domain with selectors: s1, s2
  • !
    1024-bit DKIM key
    1024-bit RSA keys are the minimum and are considered weak today: s2 (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

4 mail servers

Found

PriorityHostRecordsReverse DNS
10assur.rtl.deA 193.16.163.11assur.rtl.de ✓
10marduk.rtl.deA 193.16.163.31marduk.rtl.de ✓
20sul.rtl.deA 193.16.163.16sul.rtl.de ✓
20sulis.rtl.deA 193.16.163.17sulis.rtl.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: assur.rtl.de, marduk.rtl.de, sul.rtl.de, sulis.rtl.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
assur.rtl.denone-
marduk.rtl.denone-
sul.rtl.denone-
sulis.rtl.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