Mail domain report: kabelfoon.nl

SPF

pass

SPF record published

Found

Record: v=spf1 include:_spf.dfn.nl -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.

DMARC

fail

p=none (_dmarc.kabelfoon.nl)

Found

Record: v=DMARC1; p=none
Found at: _dmarc.kabelfoon.nl

Tag	Value	Meaning
v	DMARC1	Version
p	none	Policy

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

pass

Selectors: default

Found

Selectors: default
_domainkey: NOERROR

Selector	Key	Flags
default	RSA 2048 bits	h=sha256

Checks

✓ Keys found: default #7

DKIM keys found for this domain with selectors: default
✓ Strong keys #23

DKIM keys are strong enough: default: RSA 2048 bits.
✓ 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 (1)
DS at parent: Yes
Algorithms: ECDSAP256SHA256 (13)
Key tags: 15912
Signatures valid until: 5 November 2026, 00:00 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 2026-11-05 #21

DNSKEY signatures are valid until 2026-11-05T00:00:00Z.

MX

warn

4 mail servers

Found

Priority	Host	Records	Reverse DNS
10	mx1.caiway.net	A 217.102.255.221 A 217.102.255.220 A 217.102.255.215 A 217.102.255.218 A 217.102.255.217 A 217.102.255.222 A 217.102.255.223 A 217.102.255.219 A 217.102.255.224	spamfilter21.delta.nl ✓ spamfilter20.delta.nl ✓ spamfilter15.delta.nl ✓ spamfilter18.delta.nl ✓ spamfilter17.delta.nl ✓ spamfilter22.delta.nl ✓ spamfilter23.delta.nl ✓ spamfilter19.delta.nl ✓ spamfilter24.delta.nl ✓
20	mx2.caiway.net	A 217.102.255.240 A 217.102.255.238 A 217.102.255.239 A 217.102.255.236 A 217.102.255.237	spamfilter20.delta.nl (does not resolve back) spamfilter18.delta.nl (does not resolve back) spamfilter19.delta.nl (does not resolve back) spamfilter16.delta.nl (does not resolve back) spamfilter17.delta.nl (does not resolve back)
30	mx3.caiway.net	A 217.102.255.236 A 217.102.255.237 A 217.102.255.238 A 217.102.255.240 A 217.102.255.239	spamfilter16.delta.nl (does not resolve back) spamfilter17.delta.nl (does not resolve back) spamfilter18.delta.nl (does not resolve back) spamfilter20.delta.nl (does not resolve back) spamfilter19.delta.nl (does not resolve back)
40	mx4.caiway.net	A 217.102.255.246 A 217.102.255.247 A 217.102.255.251 A 217.102.255.245 A 217.102.255.240	spamfilter22.delta.nl (does not resolve back) spamfilter23.delta.nl (does not resolve back) spamfilter24.delta.nl (does not resolve back) spamfilter21.delta.nl (does not resolve back) spamfilter20.delta.nl (does not resolve back)

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: mx1.caiway.net, mx2.caiway.net, mx3.caiway.net, mx4.caiway.net

#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 does not match

The PTR name of these addresses does not resolve back to the same address: 217.102.255.240 -> spamfilter20.delta.nl, 217.102.255.238 -> spamfilter18.delta.nl, 217.102.255.239 -> spamfilter19.delta.nl, 217.102.255.236 -> spamfilter16.delta.nl, 217.102.255.237 -> spamfilter17.delta.nl, 217.102.255.236 -> spamfilter16.delta.nl, 217.102.255.237 -> spamfilter17.delta.nl, 217.102.255.238 -> spamfilter18.delta.nl, 217.102.255.240 -> spamfilter20.delta.nl, 217.102.255.239 -> spamfilter19.delta.nl, 217.102.255.246 -> spamfilter22.delta.nl, 217.102.255.247 -> spamfilter23.delta.nl, 217.102.255.251 -> spamfilter24.delta.nl, 217.102.255.245 -> spamfilter21.delta.nl, 217.102.255.240 -> spamfilter20.delta.nl.

#30

TLS

info

no MTA-STS · no TLS-RPT · DANE on 0 of 4 MX hosts

Found

DANE (TLSA records)

MX host	TLSA	DNSSEC
mx1.caiway.net	none	-
mx2.caiway.net	none	-
mx3.caiway.net	none	-
mx4.caiway.net	none	-

Lookup error: DNS query for _mta-sts.kabelfoon.nl returned SERVFAIL

Checks

i

Could not be checked

The MTA-STS lookup failed, so this could not be checked: DNS query for _mta-sts.kabelfoon.nl returned SERVFAIL

#32
i

Could not be checked

The TLS-RPT lookup failed, so this could not be checked: DNS query for _smtp._tls.kabelfoon.nl returned SERVFAIL

#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

DNS query for default._bimi.kabelfoon.nl returned SERVFAIL

Checks

i

Could not be checked

The BIMI lookup failed, so this could not be checked: DNS query for default._bimi.kabelfoon.nl returned SERVFAIL

#38