th-nuernberg.de

Checked 22 October 2026, 00:40 UTC · via 8.8.8.8
✗Problems found
23 passed 3 warnings 1 failed 3 info

SPF

pass

SPF record published

Found

Record
v=spf1 mx a:mailgw2.th-nuernberg.de a:bvbvxmail.bib-bvb.de a:mailer02.zib.de include:_spf.kdv-fh-bayern.de include:_spf.mail.lrz.de include:spf.protection.outlook.com -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

fail

p=none (_dmarc.th-nuernberg.de)

Found

Record
v=DMARC1; p=none;
Found at
_dmarc.th-nuernberg.de
TagValueMeaning
vDMARC1Version
pnonePolicy

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

DKIM

pass

Selectors: selector1, selector2

Found

Selectors
selector1, selector2
_domainkey
NOERROR
SelectorKeyFlags
selector1RSA 2048 bits
selector2RSA 2048 bits

Checks

  • ✓ Keys found: selector1, selector2 #7
    DKIM keys found for this domain with selectors: selector1, selector2
  • ✓ Strong keys #23
    DKIM keys are strong enough: selector1: RSA 2048 bits; selector2: 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
40297, 45246
Signatures valid until
20 November 2026, 20:00 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 2026-11-20 #21
    DNSKEY signatures are valid until 2026-11-20T20:00:01Z.

MX

warn

1 mail server

Found

PriorityHostRecordsReverse DNS
0thnuernberg-de0e.mail.protection.outlook.comA 52.101.91.159 A 52.101.103.36 A 52.101.185.21 A 52.101.68.8 AAAA 2a01:111:f403:ca21::e AAAA 2a01:111:f403:ca48::8 AAAA 2a01:111:f403:ca04::a AAAA 2a01:111:f403:ca04::cmail-matpr04cu00207.inbound.protection.outlook.com ✓ mail-miypr05cu00104.inbound.protection.outlook.com ✓ mail-zrxpr05cu00105.inbound.protection.outlook.com ✓ mail-du0pr03cu00100.inbound.protection.outlook.com ✓ mail-matpr04cu00306.inbound.protection.outlook.com ✓ mail-miypr02cu00100.inbound.protection.outlook.com ✓ mail-du0pr03cu00102.inbound.protection.outlook.com ✓ mail-db9pr02cu00204.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.
  • ✓ All hosts have IPv6 #11
    All MX records resolve to IPv6 addresses.
  • !
    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 8 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
thnuernberg-de0e.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