lrz-muenchen.de

Checked 21 October 2026, 23:20 UTC · via 8.8.8.8
✗Problems found
19 passed 2 warnings 2 failed 2 info

SPF

info

SPF record published

Found

Record
v=spf1 redirect=_spf.mail.lrz.de
DNS lookups
1 of 10
Void lookups
0 of 2

Checks

  • ✓ No deprecated ptr mechanism #1
    No ptr mechanism found in SPF record.
  • ✓ 1 of 10 DNS lookups #2
    SPF record needs 1 DNS lookups (limit is 10).
  • i
    Delegated via redirect
    SPF record has no 'all' mechanism but redirects to _spf.mail.lrz.de, whose policy applies.
    #3
  • ✓ 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.lrz-muenchen.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 (3)
DS at parent
Yes
Algorithms
RSASHA256 (8)
Key tags
33859, 27349, 13300
Signatures valid until
20 December 2026, 12:48 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 2026-12-20 #21
    DNSKEY signatures are valid until 2026-12-20T12:48:00Z.

MX

pass

2 mail servers

Found

PriorityHostRecordsReverse DNS
100postrelay1.lrz.deA 129.187.255.160 A 129.187.254.158 AAAA 2001:4ca0:0:103:0:25:1:1 AAAA 2001:4ca0:0:103::81bb:ffa0postrelay1b.lrz.de ✓ postrelay1a.lrz.de ✓ postrelay1a.lrz.de ✓ postrelay1b.lrz.de ✓
100postrelay2.lrz.deA 129.187.255.161 A 129.187.254.159 AAAA 2001:4ca0:0:103::81bb:ffa1 AAAA 2001:4ca0:0:103:0:25:1:2postrelay2b.lrz.de ✓ postrelay2a.lrz.de ✓ postrelay2b.lrz.de ✓ postrelay2a.lrz.de ✓

Checks

  • ✓ 2 MX records #9
    Found 2 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 2 MX records, which provides redundancy for email delivery.
  • ✓ At most 5 MX records #13
    Found 2 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 2 of 2 MX hosts

Found

DANE (TLSA records)

MX hostTLSADNSSEC
postrelay1.lrz.de3 1 1 3d805975a26979f6…Yes
postrelay2.lrz.de3 1 1 aa00d3fd8f372d50…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 2 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