tu-chemnitz.de

SPF record published

Found

Record

v=spf1 ip4:134.109.229.63 ip4:134.109.229.193 ip6:2001:638:911:b0e:134:109:229:63 ip6:2001:638:911:b0e:134:109:229:193 include:_spf.o155.mx.srv.dfn.de ~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.

p=reject (_dmarc.tu-chemnitz.de)

Found

Record

v=DMARC1; p=reject; rua=mailto:dmarc-reports@hrz.tu-chemnitz.de

Found at

_dmarc.tu-chemnitz.de

Checks

• ✓ Policy: reject #4

  DMARC policy is set to 'reject', which provides the strongest protection against email spoofing.
• ✓ 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-reports@hrz.tu-chemnitz.de
• ✓ Subdomain policy: reject #20

  Subdomains are covered by policy 'reject'.
• ✓ Report addresses in own domain #29

  All report addresses are in your own organizational domain.

Signed, DS published at parent

Found

DNSKEY records

Yes (2)

DS at parent

Yes

Algorithms

RSASHA256 (8)

Key tags

40654, 1039

Signatures valid until

29 October 2026, 03:45 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 2026-10-29 #21

  DNSKEY signatures are valid until 2026-10-29T03:45:38Z.

2 mail servers

Found

Checks

• ✓ 2 MX records #9

  Found 2 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 2 MX records, which provides redundancy for email delivery.
• ✓ At most 5 MX records #13

  Found 2 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.