uni-hd.de

Checked 22 October 2026, 00:50 UTC · via 8.8.8.8
✗Problems found
22 passed 4 warnings 1 failed 3 info

SPF

pass

SPF record published

Found

Record
v=spf1 ip4:129.206.100.212 ip4:129.206.119.212 ip4:129.206.100.213 ip4:129.206.119.213 ip4:129.206.100.214 -all
DNS lookups
0 of 10
Void lookups
0 of 2

Checks

  • ✓ No deprecated ptr mechanism #1
    No ptr mechanism found in SPF record.
  • ✓ 0 of 10 DNS lookups #2
    SPF record needs 0 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.uni-hd.de)

Found

Record
v=DMARC1; p=none; adkim=r; aspf=r; rua=mailto:dmarc@exchange.uni-heidelberg.de
Found at
_dmarc.uni-hd.de
External report address
mailto:dmarc@exchange.uni-heidelberg.de (not authorized)
TagValueMeaning
vDMARC1Version
pnonePolicy
ruamailto:dmarc@exchange.uni-heidelberg.deAggregate report addresses
adkimrDKIM alignment (r = relaxed, s = strict)
aspfrSPF alignment (r = relaxed, s = strict)

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.
  • ✓ Aggregate reports enabled #19
    Aggregate reports are sent to: mailto:dmarc@exchange.uni-heidelberg.de
  • !
    Report address not authorized
    These report addresses are in another domain that has not agreed to receive your reports, so receivers will not send them: mailto:dmarc@exchange.uni-heidelberg.de (needs uni-hd.de._report._dmarc.exchange.uni-heidelberg.de). Ask the report provider to publish the record, or check the address.
    #29

DKIM

pass

Selectors: s1

Found

Selectors
s1
_domainkey
NOERROR
SelectorKeyFlags
s1RSA 2048 bits

Checks

  • ✓ Keys found: s1 #7
    DKIM keys found for this domain with selectors: s1
  • ✓ Strong keys #23
    DKIM keys are strong enough: s1: 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

3 mail servers

Found

PriorityHostRecordsReverse DNS
10relay.uni-heidelberg.deA 129.206.100.212relay.uni-heidelberg.de ✓
10relay2.uni-heidelberg.deA 129.206.119.212relay2.uni-heidelberg.de ✓
10relay3.uni-heidelberg.deA 129.206.100.213relay3.uni-heidelberg.de ✓

Checks

  • ✓ 3 MX records #9
    Found 3 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: relay.uni-heidelberg.de, relay2.uni-heidelberg.de, relay3.uni-heidelberg.de
    #11
  • ✓ 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 3 MX addresss have a PTR record that resolves back to them.

TLS

warn

no MTA-STS · no TLS-RPT · DANE on 0 of 3 MX hosts

Found

DANE (TLSA records)

MX hostTLSADNSSEC
relay.uni-heidelberg.denone-
relay2.uni-heidelberg.denone-
relay3.uni-heidelberg.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