stl.nl

Checked 22 October 2026, 16:20 UTC · via 8.8.8.8
!Passed with warnings
24 passed 4 warnings 0 failed 3 info

SPF

pass

SPF record published

Found

Record
v=spf1 include:spf.protection.outlook.com -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

warn

p=quarantine (_dmarc.stl.nl)

Found

Record
v=DMARC1; p=quarantine; sp=none; rua=mailto:watchdog5@watchdog.kevlarr.io; adkim=r; aspf=r;
Found at
_dmarc.stl.nl
External report address
mailto:watchdog5@watchdog.kevlarr.io (authorized)
TagValueMeaning
vDMARC1Version
pquarantinePolicy
spnoneSubdomain policy
ruamailto:watchdog5@watchdog.kevlarr.ioAggregate report addresses
adkimrDKIM alignment (r = relaxed, s = strict)
aspfrSPF alignment (r = relaxed, s = strict)

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:watchdog5@watchdog.kevlarr.io
  • !
    Subdomains unprotected (sp=none)
    DMARC subdomain policy is sp=none, so spoofed mail from subdomains is not blocked. Consider sp=quarantine or sp=reject.
    #20
  • ✓ External report addresses authorized #29
    Report addresses in other domains have published their authorization.

DKIM

warn

No keys found under the checked selectors

Found

Selectors
None found
_domainkey
NOERROR

Checks

  • !
    No key under common selectors
    The _domainkey name exists but no DKIM key was found under the common selectors. Selectors are provider-specific; check yours with -selector.
    #7

DNSSEC

pass

Signed, DS published at parent

Found

DNSKEY records
Yes (2)
DS at parent
Yes
Algorithms
RSASHA256 (8)
Key tags
32135, 4375
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

pass

3 mail servers

Found

PriorityHostRecordsReverse DNS
0stl-nl.mail.protection.outlook.comA 52.101.73.155 A 52.101.103.36 A 52.101.181.156 A 52.101.185.21 AAAA 2a01:111:f403:ca09::28 AAAA 2a01:111:f403:ca21::10 AAAA 2a01:111:f403:ca21::e AAAA 2a01:111:f403:ca38::amail-am7pr02cu00203.inbound.protection.outlook.com ✓ mail-miypr05cu00104.inbound.protection.outlook.com ✓ mail-wa4pr05cu00104.inbound.protection.outlook.com ✓ mail-zrxpr05cu00105.inbound.protection.outlook.com ✓ mail-am6pr02cu00300.inbound.protection.outlook.com ✓ mail-matpr05cu00100.inbound.protection.outlook.com ✓ mail-matpr04cu00306.inbound.protection.outlook.com ✓ mail-wa4pr05cu00102.inbound.protection.outlook.com ✓
10primary.yourfilter.nlA 185.223.33.29 A 185.223.33.23 A 185.223.33.24 A 185.103.241.20 A 185.103.241.22 A 185.103.241.23 A 185.103.241.21 A 185.223.33.28 A 185.103.241.25 A 185.223.33.27 A 185.223.33.30 AAAA 2a05:1500:702:9:1c00:7fff:fe00:5556 AAAA 2a01:b941:2::28 AAAA 2a05:1500:702:9:1c00:f0ff:fe00:5555 AAAA 2a01:b941:2::26 AAAA 2a01:b941:2::24 AAAA 2a05:1500:702:9:1c00:a3ff:fe00:5558 AAAA 2a05:1500:702:9:1c00:a5ff:fe00:5553 AAAA 2a01:b941:2::23 AAAA 2a05:1500:702:9:1c00:2aff:fe00:5554 AAAA 2a01:b941:2::25 AAAA 2a01:b941:2::29 AAAA 2a01:b941:2::27 AAAA 2a01:b941:2::30se17-yh.route25.eu ✓ se23-yh.route25.eu ✓ se22-yh.route25.eu ✓ se27-yh.route25.eu ✓ se29-yh.route25.eu ✓ se30-yh.route25.eu ✓ se28-yh.route25.eu ✓ se18-yh.route25.eu ✓ se26-yh.route25.eu ✓ se19-yh.route25.eu ✓ se16-yh.route25.eu ✓ se30-yh.route25.eu ✓ se18-yh.route25.eu ✓ se29-yh.route25.eu ✓ se20-yh.route25.eu ✓ se22-yh.route25.eu ✓ se26-yh.route25.eu ✓ se27-yh.route25.eu ✓ se23-yh.route25.eu ✓ se28-yh.route25.eu ✓ se21-yh.route25.eu ✓ se17-yh.route25.eu ✓ se19-yh.route25.eu ✓ se16-yh.route25.eu ✓
20fallback.yourfilter.nlA 185.223.33.23 A 185.223.33.25 A 185.103.241.22 A 185.223.33.26 A 185.103.241.23 A 185.223.33.27 A 185.223.33.30 AAAA 2a01:b941:2::30 AAAA 2a01:b941:2::29 AAAA 2a01:b941:2::28 AAAA 2a01:b941:2::23 AAAA 2a05:1500:702:9:1c00:7fff:fe00:5556 AAAA 2a01:b941:2::24 AAAA 2a05:1500:702:9:1c00:f0ff:fe00:5555se23-yh.route25.eu ✓ se21-yh.route25.eu ✓ se29-yh.route25.eu ✓ se20-yh.route25.eu ✓ se30-yh.route25.eu ✓ se19-yh.route25.eu ✓ se16-yh.route25.eu ✓ se16-yh.route25.eu ✓ se17-yh.route25.eu ✓ se18-yh.route25.eu ✓ se23-yh.route25.eu ✓ se30-yh.route25.eu ✓ se22-yh.route25.eu ✓ se29-yh.route25.eu ✓

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.
  • ✓ No CNAME targets #22
    No MX records point to a CNAME.
  • ✓ Reverse DNS confirmed #30
    All 46 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 hostTLSADNSSEC
stl-nl.mail.protection.outlook.comnone-
primary.yourfilter.nlnone-
fallback.yourfilter.nlnone-

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