network-science.de

SPF record published

Found

Record

v=spf1 a:www.geektool.de a:mail.geektool.de a:smtp.geektool.de a:geektool.de a:red.geektool.de mx:MX mx:mail.geektool.de mx:MX mx:mail.x-cellent.com include:mail.x-cellent.com ~all

DNS lookups

10 of 10

Void lookups

1 of 2

Problem

include:mail.x-cellent.com does not exist or has no records

Checks

• ✓ No deprecated ptr mechanism #1

  No ptr mechanism found in SPF record.
• !

  10 of 10 DNS lookups, with problems

  SPF record needs 10 DNS lookups (limit is 10). Problems found: include:mail.x-cellent.com does not exist or has no records.

  #2
• ✓ 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.
• !

  1 void lookup

  1 include/redirect target does not exist or has no records (limit is 2). This usually is a stale include; remove it.

  #26
• ✓ No overly broad IP ranges #27

  All ip4/ip6 ranges are narrow enough.

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

1 mail server

Found

Checks

• ✓ 1 MX record #9

  Found 1 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: mail.geektools.de

  #11
• !

  Single MX host, no backup

  Only one MX record found. For better email reliability, consider adding at least one backup MX server.

  #12
• ✓ At most 5 MX records #13

  Found 1 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 1 MX address have a PTR record that resolves back to them.

no MTA-STS · no TLS-RPT · DANE on 0 of 1 MX hosts

Found

DANE (TLSA records)

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