Mail domain report: studytube.nl

SPF

pass

SPF record published

Found

Record: v=spf1 include:_spf_by_autospf_com.studytube.nl ~all
DNS lookups: 7 of 10
Void lookups: 0 of 2

Checks

✓ No deprecated ptr mechanism #1

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

SPF record needs 7 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.studytube.nl)

Found

Record: v=DMARC1; p=quarantine; sp=none; rua=mailto:re+11b6a84c31bb@inbound.dmarcdigests.com; aspf=r; pct=100
Found at: _dmarc.studytube.nl
External report address: mailto:re+11b6a84c31bb@inbound.dmarcdigests.com (authorized)

Tag	Value	Meaning
v	DMARC1	Version
p	quarantine	Policy
sp	none	Subdomain policy
pct	100	Percentage of mail the policy applies to
rua	mailto:re+11b6a84c31bb@inbound.dmarcdigests.com	Aggregate report addresses
aspf	r	SPF 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:re+11b6a84c31bb@inbound.dmarcdigests.com
!

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

Selectors: mail, email, k1, google

Found

Selectors: mail, email, k1, google
_domainkey: NOERROR

Selector	Key	Flags
mail	RSA 1024 bits
email	RSA 1024 bits
k1	RSA 1024 bits
google	RSA 1024 bits

Checks

✓ Keys found: mail, email, k1, google #7

DKIM keys found for this domain with selectors: mail, email, k1, google
!

1024-bit DKIM key

1024-bit RSA keys are the minimum and are considered weak today: mail (1024 bits), email (1024 bits), k1 (1024 bits), google (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: ECDSAP256SHA256 (13)
Key tags: 36016, 60559, 47858, 10896
Signatures valid until: 23 October 2026, 02:00 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 expire in 10h0m0s

DNSKEY signatures expire at 2026-10-23T02:00:00Z (in 10h0m0s). Check that re-signing works.

#21

MX

pass

5 mail servers

Found

Priority	Host	Records	Reverse DNS
1	aspmx.l.google.com	A 142.251.127.27 AAAA 2a00:1450:400c:c04::1b	lcfrai-in-f27.1e100.net ✓ wk-in-f27.1e100.net ✓
5	alt1.aspmx.l.google.com	A 142.250.147.27 AAAA 2a00:1450:4025:c01::1b	rd-in-f27.1e100.net ✓ rd-in-f27.1e100.net ✓
5	alt2.aspmx.l.google.com	A 172.253.152.26 AAAA 2a00:1450:4010:c22::1b	yulpptr-in-f26.1e100.net ✓ yulpptr-in-f27.1e100.net ✓
10	aspmx2.googlemail.com	A 142.250.147.27 AAAA 2a00:1450:4025:c01::1a	rd-in-f27.1e100.net ✓ rd-in-f26.1e100.net ✓
10	aspmx3.googlemail.com	A 172.253.152.27 AAAA 2a00:1450:4010:c22::1b	yulpptr-in-f27.1e100.net ✓ yulpptr-in-f27.1e100.net ✓

Checks

✓ 5 MX records #9

Found 5 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 5 MX records, which provides redundancy for email delivery.
✓ At most 5 MX records #13

Found 5 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 10 MX addresss have a PTR record that resolves back to them.

TLS

warn

no MTA-STS · no TLS-RPT · DANE on 0 of 5 MX hosts

Found

DANE (TLSA records)

MX host	TLSA	DNSSEC
aspmx.l.google.com	none	-
alt1.aspmx.l.google.com	none	-
alt2.aspmx.l.google.com	none	-
aspmx2.googlemail.com	none	-
aspmx3.googlemail.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

fail

https://files-730335670670-eu-central-1.s3.eu-central-1.amazonaws.com/studytube.svg

Found

Record: v=BIMI1; l=https://files-730335670670-eu-central-1.s3.eu-central-1.amazonaws.com/studytube.svg
Found at: default._bimi.studytube.nl
Logo: https://files-730335670670-eu-central-1.s3.eu-central-1.amazonaws.com/studytube.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 not strict enough for BIMI

Mail clients will not show the logo. BIMI requires a subdomain policy other than sp=none.

#39