Mail domain report: summacollege.nl

SPF

pass

SPF record published

Found

Record: v=spf1 ip4:194.171.48.136 ip4:194.171.48.179 include:spf.protection.outlook.com include:servers.mcsv.net include:spf.mandrillapp.com include:_spf.spotler.email -all
DNS lookups: 4 of 10
Void lookups: 0 of 2

Checks

✓ No deprecated ptr mechanism #1

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

SPF record needs 4 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.summacollege.nl)

Found

Record: v=DMARC1; p=reject; rua=mailto:dmarc_agg@vali.email; ruf=mailto:dmarc-ruf@summacollege.nl; rf=afrf; sp=reject; fo=1; adkim=s; aspf=r
Found at: _dmarc.summacollege.nl
External report address: mailto:dmarc_agg@vali.email (authorized)

Tag	Value	Meaning
v	DMARC1	Version
p	reject	Policy
sp	reject	Subdomain policy
rua	mailto:dmarc_agg@vali.email	Aggregate report addresses
ruf	mailto:dmarc-ruf@summacollege.nl	Failure report addresses
adkim	s	DKIM alignment (r = relaxed, s = strict)
aspf	r	SPF alignment (r = relaxed, s = strict)
fo	1	Failure reporting options
rf	afrf	Failure 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_agg@vali.email
✓ 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: k1, selector2

Found

Selectors: k1, selector2
_domainkey: NOERROR

Selector	Key	Flags
k1	RSA 1024 bits
selector2	RSA 1024 bits

Checks

✓ Keys found: k1, selector2 #7

DKIM keys found for this domain with selectors: k1, selector2
!

1024-bit DKIM key

1024-bit RSA keys are the minimum and are considered weak today: k1 (1024 bits), selector2 (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 (4)
DS at parent: Yes
Algorithms: ECDSAP256SHA256 (13)
Key tags: 23283, 42500, 45734, 50122
Signatures valid until: 14 November 2026, 00:02 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 2026-11-14 #21

DNSKEY signatures are valid until 2026-11-14T00:02:01Z.

MX

warn

1 mail server

Found

Priority	Host	Records	Reverse DNS
10	summacollege-nl.l-v1.mx.microsoft	A 52.101.181.156 A 52.101.73.123 A 52.101.68.21 A 52.101.185.24 AAAA 2a01:111:f403:ca21::8 AAAA 2a01:111:f403:c967::c AAAA 2a01:111:f403:ca04::d AAAA 2a01:111:f403:ca04::f	mail-wa4pr05cu00104.inbound.protection.outlook.com ✓ mail-am6pr02cu00203.inbound.protection.outlook.com ✓ mail-db4pr02cu00205.inbound.protection.outlook.com ✓ mail-zrxpr07cu00100.inbound.protection.outlook.com ✓ mail-matpr04cu00100.inbound.protection.outlook.com ✓ mail-cpjpr05cu00204.inbound.protection.outlook.com ✓ mail-db6pr03cu00105.inbound.protection.outlook.com ✓ mail-db7pr03cu00507.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 1 of 1 MX hosts

Found

DANE (TLSA records)

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

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
!

Not configured

MTA-STS or DANE is used without TLS-RPT, so you get no reports when senders fail to deliver because of TLS problems. Publish _smtp._tls TXT "v=TLSRPTv1; rua=mailto:...".

#35
✓ DANE on all MX hosts #36

All 1 MX host publish DNSSEC-validated TLSA records.

BIMI

warn

https://summa-onderwijs.nl/app/themes/summa-onderwijs/assets/icons/logo-bimi.svg

Found

Record: v=BIMI1; l=https://summa-onderwijs.nl/app/themes/summa-onderwijs/assets/icons/logo-bimi.svg;
Found at: default._bimi.summacollege.nl
Logo: https://summa-onderwijs.nl/app/themes/summa-onderwijs/assets/icons/logo-bimi.svg

Checks

!

No certificate (a=)

The logo is published without a Verified Mark Certificate. Gmail and Apple Mail only show BIMI logos with a VMC or CMC; Yahoo shows it without one.

#38
✓ DMARC meets BIMI requirements #39

DMARC is enforced on all mail, as BIMI requires.