Mail domain report: sans-online.nl

SPF

pass

SPF record published

Found

Record: v=spf1 a:sansonlineweb.svr.previder.nl a:sansonlineservice.svr.previder.nl a:sansonlineacc.svr.previder.nl ip4:83.96.253.144 ip4:145.131.10.247 ip4:178.251.197.86 ip4:178.251.197.88 include:trustpilotservice.com include:_spf.yourfilter.nl include:spf.protection.outlook.com ~all
DNS lookups: 10 of 10
Void lookups: 0 of 2

Checks

✓ No deprecated ptr mechanism #1

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

SPF record needs 10 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.sans-online.nl)

Found

Record: v=DMARC1; p=none; aspf=s; pct=100; ri=1800; rua=mailto:tom@sans-online.nl; ruf=mailto:tom@sans-online.nl;
Found at: _dmarc.sans-online.nl

Tag	Value	Meaning
v	DMARC1	Version
p	none	Policy
pct	100	Percentage of mail the policy applies to
rua	mailto:tom@sans-online.nl	Aggregate report addresses
ruf	mailto:tom@sans-online.nl	Failure report addresses
aspf	s	SPF alignment (r = relaxed, s = strict)
ri	1800	Report interval (seconds)

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.
✓ Aggregate reports enabled #19

Aggregate reports are sent to: mailto:tom@sans-online.nl
✓ Report addresses in own domain #29

All report addresses are in your own organizational domain.

DKIM

pass

Selectors: default, selector1, selector2

Found

Selectors: default, selector1, selector2
_domainkey: NOERROR

Selector	Key	Flags
default	RSA 2048 bits
selector1	RSA 2048 bits
selector2	RSA 2048 bits

Checks

✓ Keys found: default, selector1, selector2 #7

DKIM keys found for this domain with selectors: default, selector1, selector2
✓ Strong keys #23

DKIM keys are strong enough: default: RSA 2048 bits; selector1: RSA 2048 bits; selector2: 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 (2)
DS at parent: Yes
Algorithms: RSASHA256 (8)
Key tags: 5071, 20816
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

1 mail server

Found

Priority	Host	Records	Reverse DNS
10	sansonline-nl01b.mail.protection.outlook.com	A 52.101.185.24 A 52.101.68.8 A 52.101.68.15 A 52.101.103.36 AAAA 2a01:111:f403:ca48::c AAAA 2a01:111:f403:ca3c::a AAAA 2a01:111:f403:ca38::a AAAA 2a01:111:f403:ca21::a	mail-zrxpr07cu00100.inbound.protection.outlook.com ✓ mail-du0pr03cu00100.inbound.protection.outlook.com ✓ mail-db6pr03cu00107.inbound.protection.outlook.com ✓ mail-miypr05cu00104.inbound.protection.outlook.com ✓ mail-miypr03cu00104.inbound.protection.outlook.com ✓ mail-zrxpr07cu00102.inbound.protection.outlook.com ✓ mail-wa4pr05cu00102.inbound.protection.outlook.com ✓ mail-maspr04cu00102.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

warn

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

Found

DANE (TLSA records)

MX host	TLSA	DNSSEC
sansonline-nl01b.mail.protection.outlook.com	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