Mail domain report: postnl.nl

SPF

pass

SPF record published

Found

Record: v=spf1 ip4:87.233.130.51 ip4:83.149.98.72 include:spf.protection.outlook.com include:spf1.postnl.nl include:spf2.postnl.nl include:spf.topdesk.net -all
DNS lookups: 6 of 10
Void lookups: 0 of 2

Checks

✓ No deprecated ptr mechanism #1

No ptr mechanism found in SPF record.
✓ 6 of 10 DNS lookups #2

SPF record needs 6 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

pass

p=reject (_dmarc.postnl.nl)

Found

Record: v=DMARC1; p=reject; rua=mailto:m9sha5zi@rua.eu.dmarcmanager.app; ruf=mailto:m9sha5zi@ruf.eu.dmarcmanager.app;
Found at: _dmarc.postnl.nl
External report address: mailto:m9sha5zi@rua.eu.dmarcmanager.app (authorized)
External report address: mailto:m9sha5zi@ruf.eu.dmarcmanager.app (authorized)

Tag	Value	Meaning
v	DMARC1	Version
p	reject	Policy
rua	mailto:m9sha5zi@rua.eu.dmarcmanager.app	Aggregate report addresses
ruf	mailto:m9sha5zi@ruf.eu.dmarcmanager.app	Failure report addresses

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:m9sha5zi@rua.eu.dmarcmanager.app
✓ Subdomain policy: reject #20

Subdomains are covered by policy 'reject'.
✓ External report addresses authorized #29

Report addresses in other domains have published their authorization.

DKIM

warn

Selectors: selector1, s1, s2

Found

Selectors: selector1, s1, s2
_domainkey: NOERROR

Selector	Key	Flags
selector1	RSA 1024 bits
s1	RSA 2048 bits
s2	RSA 1024 bits

Checks

✓ Keys found: selector1, s1, s2 #7

DKIM keys found for this domain with selectors: selector1, s1, s2
!

1024-bit DKIM key

1024-bit RSA keys are the minimum and are considered weak today: selector1 (1024 bits), s2 (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

Signed, DS published at parent

Found

DNSKEY records: Yes (3)
DS at parent: Yes
Algorithms: RSASHA512 (10)
Key tags: 37447, 54891, 9735
Signatures valid until: 24 October 2026, 20:28 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 expire in 71h0m0s

DNSKEY signatures expire at 2026-10-24T20:28:48Z (in 71h0m0s). Check that re-signing works.

#21

MX

warn

1 mail server

Found

Priority	Host	Records	Reverse DNS
10	postnl-nl.j-v1.mx.microsoft	A 52.101.91.21 A 52.101.91.153 A 52.101.103.162 A 52.101.103.39 AAAA 2a01:111:f403:ca09::22 AAAA 2a01:111:f403:ca21::10 AAAA 2a01:111:f403:ca04::10 AAAA 2a01:111:f403:ca09::26	mail-matpr05cu00105.inbound.protection.outlook.com ✓ mail-matpr04cu00101.inbound.protection.outlook.com ✓ mail-miypr03cu00202.inbound.protection.outlook.com ✓ mail-miypr05cu00207.inbound.protection.outlook.com ✓ mail-am7pr02cu00302.inbound.protection.outlook.com ✓ mail-matpr05cu00100.inbound.protection.outlook.com ✓ mail-dbapr03cu00100.inbound.protection.outlook.com ✓ mail-am8pr83cu00106.inbound.protection.outlook.com ✓

Checks

✓ 1 MX record #9

Found 1 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.
!

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 8 MX addresss have a PTR record that resolves back to them.

TLS

pass

MTA-STS enforce · TLS-RPT · DANE on 1 of 1 MX hosts

Found

MTA-STS record: v=STSv1; id=20260828
Policy URL: https://mta-sts.postnl.nl/.well-known/mta-sts.txt
Mode: enforce
Allowed MX: postnl-nl.j-v1.mx.microsoft
Max age: 86400 seconds
TLS-RPT record: v=TLSRPTv1; rua=mailto:m9sha5zi@tls.eu.dmarcmanager.app,mailto:m9sha5zi@tls.eu.dmarcadvisor.com;

DANE (TLSA records)

MX host	TLSA	DNSSEC
postnl-nl.j-v1.mx.microsoft	2 0 1 c1ad7778796d20bc… 2 0 1 ea7a25255d111fc3… 3 1 1 803f7447cc75b208… 3 1 1 54883cc5f1849331… 3 1 1 cfd68bde4129c00a…	Yes

Checks

✓ Record published #32

MTA-STS record found with id 20260828.
✓ Policy enforced #33

The MTA-STS policy is enforced and cached for 24h0m0s.
✓ All MX hosts covered #34

Every MX host matches an mx: line of the MTA-STS policy.
✓ Reports enabled #35

TLS reports are sent to: mailto:m9sha5zi@tls.eu.dmarcmanager.app, mailto:m9sha5zi@tls.eu.dmarcadvisor.com
✓ DANE on all MX hosts #36

All 1 MX host publish DNSSEC-validated TLSA records.

BIMI

pass

https://bimi.eu.dmarcmanager.app/eu-m9sha5zi/default/logo.svg

Found

Record: v=BIMI1; l=https://bimi.eu.dmarcmanager.app/eu-m9sha5zi/default/logo.svg; a=https://bimi.eu.dmarcmanager.app/eu-m9sha5zi/default/cert.pem;
Found at: default._bimi.postnl.nl
Logo: https://bimi.eu.dmarcmanager.app/eu-m9sha5zi/default/logo.svg
Certificate: https://bimi.eu.dmarcmanager.app/eu-m9sha5zi/default/cert.pem

Checks

✓ Logo and certificate published #38

BIMI logo: https://bimi.eu.dmarcmanager.app/eu-m9sha5zi/default/logo.svg; certificate: https://bimi.eu.dmarcmanager.app/eu-m9sha5zi/default/cert.pem
✓ DMARC meets BIMI requirements #39

DMARC is enforced on all mail, as BIMI requires.