uni-mannheim.de

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

SPF

pass

SPF record published

Found

Record
v=spf1 mx a:smtp.mail.uni-mannheim.de a:sapmail.bwhsrw.de include:spf.protection.outlook.com -all
DNS lookups
4 of 10
Void lookups
0 of 2

Checks

  • ✓ No deprecated ptr mechanism #1
    No ptr mechanism found in SPF record.
  • ✓ 4 of 10 DNS lookups #2
    SPF record needs 4 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-mannheim.de)

Found

Record
v=DMARC1; p=none;
Found at
_dmarc.uni-mannheim.de
TagValueMeaning
vDMARC1Version
pnonePolicy

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.
  • !
    No aggregate reports (rua)
    DMARC record has no rua tag, so you receive no aggregate reports about who sends mail as your domain. Add rua=mailto:...
    #19

DKIM

warn

Selectors: selector1

Found

Selectors
selector1
_domainkey
NOERROR
SelectorKeyFlags
selector1RSA 1024 bits

Checks

  • ✓ Keys found: selector1 #7
    DKIM keys found for this domain with selectors: selector1
  • !
    1024-bit DKIM key
    1024-bit RSA keys are the minimum and are considered weak today: selector1 (1024 bits). Rotate to a 2048-bit key.
    #23
  • ✓ No problematic flags #24
    No keys in test mode, revoked, or limited to SHA-1.

DNSSEC

pass

Signed, DS published at parent

Found

DNSKEY records
Yes (2)
DS at parent
Yes
Algorithms
ECDSAP384SHA384 (14)
Key tags
19259, 62827
Signatures valid until
20 November 2026, 16:00 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 2026-11-20 #21
    DNSKEY signatures are valid until 2026-11-20T16:00:47Z.

MX

pass

3 mail servers

Found

PriorityHostRecordsReverse DNS
5proxmox-mg1.uni-mannheim.deA 134.155.96.104 AAAA 2001:7c0:2900:60::869b:6068proxmox-mg1.uni-mannheim.de ✓ proxmox-mg1.uni-mannheim.de ✓
5proxmox-mg2.uni-mannheim.deA 134.155.96.5 AAAA 2001:7c0:2900:60::869b:6005proxmox-mg2.uni-mannheim.de ✓ proxmox-mg2.uni-mannheim.de ✓
5proxmox-mg3.uni-mannheim.deA 134.155.96.6 AAAA 2001:7c0:2900:60::869b:6006proxmox-mg3.uni-mannheim.de ✓ proxmox-mg3.uni-mannheim.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 · no TLS-RPT · DANE on 0 of 3 MX hosts

Found

DANE (TLSA records)

MX hostTLSADNSSEC
proxmox-mg1.uni-mannheim.denone-
proxmox-mg2.uni-mannheim.denone-
proxmox-mg3.uni-mannheim.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