uni-stuttgart.de

Checked 22 October 2026, 00:50 UTC · via 8.8.8.8
✗Problems found
18 passed 2 warnings 2 failed 3 info

SPF

fail

SPF record published

Found

Record
v=spf1 include:_spf.mxex.uni-stuttgart.de include:_spf.mailrelay.uni-stuttgart.de
DNS lookups
6 of 10
Void lookups
0 of 2

Checks

  • ✓ No deprecated ptr mechanism #1
    No ptr mechanism found in SPF record.
  • ✓ 6 of 10 DNS lookups #2
    SPF record needs 6 DNS lookups (limit is 10).
  • ✗
    No 'all' mechanism
    SPF record doesn't have an 'all' mechanism. Add -all or ~all at the end of your SPF record.
    #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

warn

No keys found under the checked selectors

Found

Selectors
None found
_domainkey
NOERROR

Checks

  • !
    No key under common selectors
    The _domainkey name exists but no DKIM key was found under the common selectors. Selectors are provider-specific; check yours with -selector.
    #7

DNSSEC

pass

Signed, DS published at parent

Found

DNSKEY records
Yes (2)
DS at parent
Yes
Algorithms
ECDSAP256SHA256 (13)
Key tags
44093, 27002
Signatures valid until
15 November 2026, 05:29 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 2026-11-15 #21
    DNSKEY signatures are valid until 2026-11-15T05:29:04Z.

MX

pass

2 mail servers

Found

PriorityHostRecordsReverse DNS
10mxex1.tik.uni-stuttgart.deA 129.69.192.20 AAAA 2001:7c0:2041:24::a:1mxex1.tik.uni-stuttgart.de ✓ mxex1.tik.uni-stuttgart.de ✓
10mxex2.tik.uni-stuttgart.deA 129.69.192.21 AAAA 2001:7c0:2041:24::a:2mxex2.tik.uni-stuttgart.de ✓ mxex2.tik.uni-stuttgart.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 4 MX addresss have a PTR record that resolves back to them.

TLS

warn

no MTA-STS · no TLS-RPT · DANE on 0 of 2 MX hosts

Found

DANE (TLSA records)

MX hostTLSADNSSEC
mxex1.tik.uni-stuttgart.denone-
mxex2.tik.uni-stuttgart.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