Mail domain report: ou.nl

SPF

pass

SPF record published

Found

Record: v=spf1 mx ip4:145.20.126.12/31 ip6:2001:610:338:1030::126:12/127 ip4:194.187.45.0/26 include:spf.protection.outlook.com -all
DNS lookups: 2 of 10
Void lookups: 0 of 2

Checks

✓ No deprecated ptr mechanism #1

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

SPF record needs 2 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

warn

p=quarantine (_dmarc.ou.nl)

Found

Record: v=DMARC1;p=quarantine;rua=mailto:dmarcreports@ou.nl;ri=7;adkim=s;aspf=r;
Found at: _dmarc.ou.nl

Tag	Value	Meaning
v	DMARC1	Version
p	quarantine	Policy
rua	mailto:dmarcreports@ou.nl	Aggregate report addresses
adkim	s	DKIM alignment (r = relaxed, s = strict)
aspf	r	SPF alignment (r = relaxed, s = strict)
ri	7	Report interval (seconds)

Checks

!

Policy: quarantine

DMARC policy is set to 'quarantine'. Consider upgrading to 'reject' for stronger protection once you've verified legitimate emails are passing authentication.

#4
✓ 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:dmarcreports@ou.nl
✓ Subdomain policy: quarantine #20

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

All report addresses are in your own organizational domain.

DKIM

warn

Selectors: selector1, selector2

Found

Selectors: selector1, selector2
_domainkey: NOERROR

Selector	Key	Flags
selector1	RSA 1024 bits
selector2	RSA 2048 bits

Checks

✓ Keys found: selector1, selector2 #7

DKIM keys found for this domain with selectors: selector1, selector2
!

1024-bit DKIM key

1024-bit RSA keys are the minimum and are considered weak today: selector1 (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 (4)
DS at parent: Yes
Algorithms: RSASHA256 (8)
Key tags: 17839, 5379, 37926, 9304
Signatures valid until: 25 October 2026, 04:21 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 79h0m0s

DNSKEY signatures expire at 2026-10-25T04:21:23Z (in 79h0m0s). Check that re-signing works.

#21

MX

warn

3 mail servers

Found

Priority	Host	Records	Reverse DNS
0	ou-nl.mail.protection.outlook.com	A 52.101.68.21 A 52.101.91.156 A 52.101.73.145 A 52.101.68.39 AAAA 2a01:111:f403:ca09::a AAAA 2a01:111:f403:ca48::10 AAAA 2a01:111:f403:c967::8 AAAA 2a01:111:f403:ca38::a	mail-db4pr02cu00205.inbound.protection.outlook.com ✓ mail-maspr04cu00104.inbound.protection.outlook.com ✓ mail-am6pr02cu00301.inbound.protection.outlook.com ✓ mail-db7pr03cu00607.inbound.protection.outlook.com ✓ mail-am7pr02cu00202.inbound.protection.outlook.com ✓ mail-miypr05cu00100.inbound.protection.outlook.com ✓ mail-cpjpr04cu00100.inbound.protection.outlook.com ✓ mail-wa4pr05cu00102.inbound.protection.outlook.com ✓
10	relay.ou.nl	CNAME lnx-hrl-042v.ou.nl A 145.20.126.12 AAAA 2001:610:338:1030::126:12	mailgw1.ou.nl ✓ relay.ou.nl ✓
20	mailserv2.ou.nl	A 145.20.126.13 AAAA 2001:610:338:1030::126:13	lnx-hrl-041v.ou.nl ✓ ns2.ou.nl ✓

Checks

✓ 3 MX records #9

Found 3 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 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.
!

Hosts are CNAMEs

MX records must point to a host name with A/AAAA records, not to a CNAME: relay.ou.nl -> lnx-hrl-042v.ou.nl

#22
✓ Reverse DNS confirmed #30

All 12 MX addresss have a PTR record that resolves back to them.

TLS

warn

no MTA-STS · no TLS-RPT · DANE on 0 of 3 MX hosts

Found

DANE (TLSA records)

MX host	TLSA	DNSSEC
ou-nl.mail.protection.outlook.com	none	-
relay.ou.nl	none	-
mailserv2.ou.nl	none	-

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

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