randomhouse.de

Checked 21 October 2026, 23:52 UTC · via 8.8.8.8
!Passed with warnings
24 passed 5 warnings 0 failed 3 info

SPF

pass

SPF record published

Found

Record
v=spf1 mx include:spf.bert.group include:_spf.senders.scnem.com include:spf.servicemail24.de include:spf.protection.outlook.com a:rdm.siruphosting.de a:smtp.siruphosting.de -all
DNS lookups
7 of 10
Void lookups
0 of 2

Checks

  • ✓ No deprecated ptr mechanism #1
    No ptr mechanism found in SPF record.
  • ✓ 7 of 10 DNS lookups #2
    SPF record needs 7 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

warn

p=quarantine (_dmarc.randomhouse.de)

Found

Record
v=DMARC1; p=quarantine; sp=quarantine; rua=mailto:prh-rua@dmarc.servicemail24.de; pct=100; ri=86400
Found at
_dmarc.randomhouse.de
External report address
mailto:prh-rua@dmarc.servicemail24.de (authorized)
TagValueMeaning
vDMARC1Version
pquarantinePolicy
spquarantineSubdomain policy
pct100Percentage of mail the policy applies to
ruamailto:prh-rua@dmarc.servicemail24.deAggregate report addresses
ri86400Report interval (seconds)

Checks

  • !
    Policy: quarantine
    DMARC policy is set to 'quarantine'. Consider upgrading to 'reject' for stronger protection once you've verified legitimate emails are passing authentication.
    #4
  • ✓ 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:prh-rua@dmarc.servicemail24.de
  • ✓ Subdomain policy: quarantine #20
    Subdomains are covered by policy 'quarantine'.
  • ✓ External report addresses authorized #29
    Report addresses in other domains have published their authorization.

DKIM

pass

Selectors: selector1

Found

Selectors
selector1
_domainkey
NOERROR
SelectorKeyFlags
selector1RSA 2048 bits

Checks

  • ✓ Keys found: selector1 #7
    DKIM keys found for this domain with selectors: selector1
  • ✓ Strong keys #23
    DKIM keys are strong enough: selector1: RSA 2048 bits.
  • ✓ 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
10randomhouse-de.mail.protection.outlook.comA 52.101.185.24 A 52.101.73.123 A 52.101.103.39 A 52.101.185.114mail-zrxpr07cu00100.inbound.protection.outlook.com ✓ mail-am6pr02cu00203.inbound.protection.outlook.com ✓ mail-miypr05cu00207.inbound.protection.outlook.com ✓ mail-zrxpr04cu00102.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.
  • !
    Hosts without IPv6
    The following MX hosts could not be resolved to IPv6 addresses: randomhouse-de.mail.protection.outlook.com
    #11
  • !
    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 4 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
randomhouse-de.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