uni-potsdam.de

Checked 22 October 2026, 00:50 UTC · via 8.8.8.8
!Passed with warnings
28 passed 4 warnings 0 failed 2 info

SPF

pass

SPF record published

Found

Record
v=spf1 ip4:141.89.0.0/16 -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

warn

p=quarantine (_dmarc.uni-potsdam.de)

Found

Record
v=DMARC1; p=quarantine; rua=mailto:dmarc@ryncdhpn.uriports.com; ruf=mailto:dmarc@ryncdhpn.uriports.com; fo=1:d:s; adkim=r; aspf=r;
Found at
_dmarc.uni-potsdam.de
External report address
mailto:dmarc@ryncdhpn.uriports.com (authorized)
TagValueMeaning
vDMARC1Version
pquarantinePolicy
ruamailto:dmarc@ryncdhpn.uriports.comAggregate report addresses
rufmailto:dmarc@ryncdhpn.uriports.comFailure report addresses
adkimrDKIM alignment (r = relaxed, s = strict)
aspfrSPF alignment (r = relaxed, s = strict)
fo1:d:sFailure reporting options

Checks

  • !
    Policy: quarantine
    DMARC policy is set to 'quarantine'. Consider upgrading to 'reject' for stronger protection once you've verified legitimate emails are passing authentication.
    #4
  • ✓ Record published #5
    DMARC record exists for this domain.
  • ✓ Valid syntax #17
    DMARC record syntax is valid.
  • ✓ Applies to 100% of mail #18
    DMARC policy applies to all failing mail.
  • ✓ Aggregate reports enabled #19
    Aggregate reports are sent to: mailto:dmarc@ryncdhpn.uriports.com
  • ✓ Subdomain policy: quarantine #20
    Subdomains are covered by policy 'quarantine'.
  • ✓ External report addresses authorized #29
    Report addresses in other domains have published their authorization.

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

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

4 mail servers

Found

PriorityHostRecordsReverse DNS
10smtpin.uni-potsdam.deA 141.89.64.18smtpin.uni-potsdam.de ✓
20smtpin2.uni-potsdam.deA 141.89.65.2smtpin2.uni-potsdam.de ✓
40mx1.uni-potsdam.deA 141.89.64.18smtpin.uni-potsdam.de ✓
50mx2.uni-potsdam.deA 141.89.65.2smtpin2.uni-potsdam.de ✓

Checks

  • ✓ 4 MX records #9
    Found 4 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: smtpin.uni-potsdam.de, smtpin2.uni-potsdam.de, mx1.uni-potsdam.de, mx2.uni-potsdam.de
    #11
  • ✓ Redundant MX hosts #12
    Found 4 MX records, which provides redundancy for email delivery.
  • ✓ At most 5 MX records #13
    Found 4 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

MTA-STS testing · TLS-RPT · DANE on 0 of 4 MX hosts

Found

MTA-STS record
v=STSv1; id=20260116094948Z;
Policy URL
https://mta-sts.uni-potsdam.de/.well-known/mta-sts.txt
Mode
testing
Allowed MX
mx1.uni-potsdam.de, smtpin2.uni-potsdam.de, smtpin.uni-potsdam.de, mx2.uni-potsdam.de
Max age
86400 seconds
TLS-RPT record
v=TLSRPTv1; rua=mailto:tlsrpt@ryncdhpn.uriports.com

DANE (TLSA records)

MX hostTLSADNSSEC
smtpin.uni-potsdam.denone-
smtpin2.uni-potsdam.denone-
mx1.uni-potsdam.denone-
mx2.uni-potsdam.denone-

Checks

  • ✓ Record published #32
    MTA-STS record found with id 20260116094948Z.
  • !
    Policy in testing mode
    With mode: testing, senders only report TLS problems (via TLS-RPT) and still deliver without TLS. Switch to mode: enforce once reports are clean.
    #33
  • ✓ All MX hosts covered #34
    Every MX host matches an mx: line of the MTA-STS policy.
  • ✓ Reports enabled #35
    TLS reports are sent to: mailto:tlsrpt@ryncdhpn.uriports.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