uni-mainz.de

Checked 22 October 2026, 00:50 UTC · via 8.8.8.8
✗Problems found
22 passed 3 warnings 1 failed 2 info

SPF

pass

SPF record published

Found

Record
v=spf1 mx ip4:134.93.178.240/28 ip6:2001:4c80:40:62d::/64 ~all
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).
  • ✓ 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-mainz.de)

Found

Record
v=DMARC1; p=none; rua=mailto:d9b8ce4a@in.mailhardener.com; ruf=mailto:d9b8ce4a@in.mailhardener.com; aspf=r; adkim=r
Found at
_dmarc.uni-mainz.de
External report address
mailto:d9b8ce4a@in.mailhardener.com (authorized)
TagValueMeaning
vDMARC1Version
pnonePolicy
ruamailto:d9b8ce4a@in.mailhardener.comAggregate report addresses
rufmailto:d9b8ce4a@in.mailhardener.comFailure 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:d9b8ce4a@in.mailhardener.com
  • ✓ External report addresses authorized #29
    Report addresses in other domains have published their authorization.

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

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

pass

3 mail servers

Found

PriorityHostRecordsReverse DNS
100mailgate-1.zdv.uni-mainz.deA 134.93.178.248 AAAA 2001:4c80:40:62d::25:8mailgate-1.zdv.Uni-Mainz.DE ✓ mailgate-1.zdv.Uni-Mainz.DE ✓
100mailgate-2.zdv.uni-mainz.deA 134.93.178.249 AAAA 2001:4c80:40:62d::25:9mailgate-2.zdv.Uni-Mainz.DE ✓ mailgate-2.zdv.Uni-Mainz.DE ✓
100mailgate-3.zdv.uni-mainz.deA 134.93.178.250 AAAA 2001:4c80:40:62d::25:amailgate-3.zdv.Uni-Mainz.DE ✓ mailgate-3.zdv.Uni-Mainz.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.
  • ✓ 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 · TLS-RPT · DANE on 0 of 3 MX hosts

Found

TLS-RPT record
v=TLSRPTv1; rua=mailto:d9b8ce4a@in.mailhardener.com

DANE (TLSA records)

MX hostTLSADNSSEC
mailgate-1.zdv.uni-mainz.denone-
mailgate-2.zdv.uni-mainz.denone-
mailgate-3.zdv.uni-mainz.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
  • ✓ Reports enabled #35
    TLS reports are sent to: mailto:d9b8ce4a@in.mailhardener.com
  • 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