hku.nl

Checked 21 October 2026, 21:21 UTC · via 8.8.8.8
!Passed with warnings
27 passed 3 warnings 0 failed 3 info

SPF

pass

SPF record published

Found

Record
v=spf1 ip4:192.87.219.71 ip4:20.160.243.164 ip4:136.144.213.2 ip4:145.107.223.250 ip4:192.87.219.164 ip4:192.87.219.240 ip4:35.204.242.219 ip4:35.204.41.40 ip6:2001:610:a30:19::71 include:_spf.spotler.email include:email.activetickets.com include:_spf.salesforce.com include:mailswitch.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

pass

p=reject (_dmarc.hku.nl)

Found

Record
v=DMARC1; p=reject; rua=mailto:dmarc.nid@hku.nl; ruf=mailto:postmaster@hku.nl; fo=1; adkim=r; aspf=r; rf=afrf
Found at
_dmarc.hku.nl
TagValueMeaning
vDMARC1Version
prejectPolicy
ruamailto:dmarc.nid@hku.nlAggregate report addresses
rufmailto:postmaster@hku.nlFailure report addresses
adkimrDKIM alignment (r = relaxed, s = strict)
aspfrSPF alignment (r = relaxed, s = strict)
fo1Failure reporting options
rfafrfFailure report format

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:dmarc.nid@hku.nl
  • ✓ Subdomain policy: reject #20
    Subdomains are covered by policy 'reject'.
  • ✓ Report addresses in own domain #29
    All report addresses are in your own organizational domain.

DKIM

warn

Selectors: selector1, selector2, s1, s2

Found

Selectors
selector1, selector2, s1, s2
_domainkey
NOERROR
SelectorKeyFlags
selector1RSA 1024 bits
selector2RSA 1024 bits
s1RSA 2048 bits
s2RSA 1024 bits

Checks

  • ✓ Keys found: selector1, selector2, s1, s2 #7
    DKIM keys found for this domain with selectors: selector1, selector2, s1, s2
  • !
    1024-bit DKIM key
    1024-bit RSA keys are the minimum and are considered weak today: selector1 (1024 bits), selector2 (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

pass

Signed, DS published at parent

Found

DNSKEY records
Yes (1)
DS at parent
Yes
Algorithms
ECDSAP256SHA256 (13)
Key tags
63646
Signatures valid until
4 November 2026, 04:42 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 2026-11-04 #21
    DNSKEY signatures are valid until 2026-11-04T04:42:58Z.

MX

warn

1 mail server

Found

PriorityHostRecordsReverse DNS
10hku-nl.mail.protection.outlook.comA 52.101.209.28 A 52.101.91.162 A 52.101.181.156 A 52.101.103.39 AAAA 2a01:111:f403:ca04::b AAAA 2a01:111:f403:ca21::8 AAAA 2a01:111:f403:ca04::f AAAA 2a01:111:f403:ca09::20mail-cpjpr05cu00104.inbound.protection.outlook.com ✓ mail-matpr04cu00302.inbound.protection.outlook.com ✓ mail-wa4pr05cu00104.inbound.protection.outlook.com ✓ mail-miypr05cu00207.inbound.protection.outlook.com ✓ mail-dbbpr03cu00103.inbound.protection.outlook.com ✓ mail-matpr04cu00100.inbound.protection.outlook.com ✓ mail-db7pr03cu00507.inbound.protection.outlook.com ✓ mail-as8pr05cu00400.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 hostTLSADNSSEC
hku-nl.mail.protection.outlook.comnone-

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