nerdculture.de

Checked 21 October 2026, 23:31 UTC · via 8.8.8.8
!Passed with warnings
27 passed 5 warnings 0 failed 1 info

SPF

pass

SPF record published

Found

Record
v=spf1 a mx ip4:31.172.31.193/26 ip6:2a01:a700:4629::/48 -all
DNS lookups
2 of 10
Void lookups
0 of 2

Checks

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

Found

Record
v=DMARC1; p=quarantine; rua=mailto:dmarc-report@windfluechter.net; ruf=mailto:dmarc-report@windfluechter.net; rf=afrf; sp=none; fo=1; ri=86400; adkim=r; aspf=r
Found at
_dmarc.nerdculture.de
External report address
mailto:dmarc-report@windfluechter.net (authorized)
TagValueMeaning
vDMARC1Version
pquarantinePolicy
spnoneSubdomain policy
ruamailto:dmarc-report@windfluechter.netAggregate report addresses
rufmailto:dmarc-report@windfluechter.netFailure report addresses
adkimrDKIM alignment (r = relaxed, s = strict)
aspfrSPF alignment (r = relaxed, s = strict)
fo1Failure reporting options
rfafrfFailure report format
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:dmarc-report@windfluechter.net
  • !
    Subdomains unprotected (sp=none)
    DMARC subdomain policy is sp=none, so spoofed mail from subdomains is not blocked. Consider sp=quarantine or sp=reject.
    #20
  • ✓ External report addresses authorized #29
    Report addresses in other domains have published their authorization.

DKIM

warn

Selectors: selector1

Found

Selectors
selector1
_domainkey
NOERROR
SelectorKeyFlags
selector1RSA 1024 bits

Checks

  • ✓ Keys found: selector1 #7
    DKIM keys found for this domain with selectors: selector1
  • !
    1024-bit DKIM key
    1024-bit RSA keys are the minimum and are considered weak today: selector1 (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

pass

Signed, DS published at parent

Found

DNSKEY records
Yes (1)
DS at parent
Yes
Algorithms
ECDSAP256SHA256 (13)
Key tags
60619
Signatures valid until
29 October 2026, 00:00 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 2026-10-29 #21
    DNSKEY signatures are valid until 2026-10-29T00:00:00Z.

MX

pass

3 mail servers

Found

PriorityHostRecordsReverse DNS
10mailgw.windfluechter.netA 31.172.31.210 AAAA 2a01:a700:4629::210:1mailgw.windfluechter.net ✓ mailgw.windfluechter.net ✓
20mail1.windfluechter.netA 31.172.31.194 AAAA 2a01:a700:4629::194:1vserv.windfluechter.net ✓ vserv.windfluechter.net ✓
20mail2.windfluechter.netA 31.172.31.195 AAAA 2a01:a700:4629::195:1mail2.windfluechter.net ✓ mail2.windfluechter.net ✓

Checks

  • ✓ 3 MX records #9
    Found 3 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 3 MX records, which provides redundancy for email delivery.
  • ✓ At most 5 MX records #13
    Found 3 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 6 MX addresss have a PTR record that resolves back to them.

TLS

warn

no MTA-STS · no TLS-RPT · DANE on 3 of 3 MX hosts

Found

DANE (TLSA records)

MX hostTLSADNSSEC
mailgw.windfluechter.net3 1 1 026394227a746280…Yes
mail1.windfluechter.net3 1 1 44c5bbaf48079d26…Yes
mail2.windfluechter.net3 1 1 44c5bbaf48079d26…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 3 MX hosts publish DNSSEC-validated TLSA records.

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