fh-erfurt.de

Checked 21 October 2026, 22:20 UTC · via 8.8.8.8
✗Problems found
23 passed 5 warnings 1 failed 1 info

SPF

pass

SPF record published

Found

Record
v=spf1 ip4:141.24.186.224 ip4:141.24.4.8 ip4:141.24.179.56 ip4:141.24.179.34 ip4:141.24.179.35 include:_converia.fh-erfurt.de include:gbv.de include:spf.sendinblue.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.fh-erfurt.de)

Found

Record
v=DMARC1;p=none;rua=mailto:dmarc2024@tu-ilmenau.de;ruf=mailto:abuse@fh-erfurt.de;fo=1
Found at
_dmarc.fh-erfurt.de
External report address
mailto:dmarc2024@tu-ilmenau.de (authorized)
TagValueMeaning
vDMARC1Version
pnonePolicy
ruamailto:dmarc2024@tu-ilmenau.deAggregate report addresses
rufmailto:abuse@fh-erfurt.deFailure report addresses
fo1Failure reporting options

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:dmarc2024@tu-ilmenau.de
  • ✓ External report addresses authorized #29
    Report addresses in other domains have published their authorization.

DKIM

warn

Selectors: mail

Found

Selectors
mail
_domainkey
NOERROR
SelectorKeyFlags
mailRSA 1024 bits

Checks

  • ✓ Keys found: mail #7
    DKIM keys found for this domain with selectors: mail
  • !
    1024-bit DKIM key
    1024-bit RSA keys are the minimum and are considered weak today: mail (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

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
10a2371.mx.srv.dfn.deA 194.95.232.199a2371.mx.srv.dfn.de ✓
10b2371.mx.srv.dfn.deA 194.95.234.199b2371.mx.srv.dfn.de ✓
10c2371.mx.srv.dfn.deA 194.95.238.199c2371.mx.srv.dfn.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: a2371.mx.srv.dfn.de, b2371.mx.srv.dfn.de, c2371.mx.srv.dfn.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 3 of 3 MX hosts

Found

DANE (TLSA records)

MX hostTLSADNSSEC
a2371.mx.srv.dfn.de3 0 1 9bec67f55f2afdb7…Yes
b2371.mx.srv.dfn.de3 0 1 9bec67f55f2afdb7…Yes
c2371.mx.srv.dfn.de3 0 1 9bec67f55f2afdb7…Yes

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
  • !
    Not configured
    MTA-STS or DANE is used without TLS-RPT, so you get no reports when senders fail to deliver because of TLS problems. Publish _smtp._tls TXT "v=TLSRPTv1; rua=mailto:...".
    #35
  • ✓ DANE on all MX hosts #36
    All 3 MX hosts publish DNSSEC-validated TLSA records.

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