Mail domain report: do.de

SPF

pass

SPF record published

Found

Record: v=spf1 ip4:95.128.200.169 ip6:2a00:1200:0:8::a48 include:spf.sendinblue.com include:spf.crsend.com -all
DNS lookups: 2 of 10
Void lookups: 0 of 2

Checks

✓ No deprecated ptr mechanism #1

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

SPF record needs 2 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=reject (_dmarc.do.de)

Found

Record: v=DMARC1;p=reject;sp=reject;pct=100;adkim=s;aspf=s;ruf=mailto:dmarc-ruf@greenmark-it.de;
Found at: _dmarc.do.de
External report address: mailto:dmarc-ruf@greenmark-it.de (authorized)

Tag	Value	Meaning
v	DMARC1	Version
p	reject	Policy
sp	reject	Subdomain policy
pct	100	Percentage of mail the policy applies to
ruf	mailto:dmarc-ruf@greenmark-it.de	Failure report addresses
adkim	s	DKIM alignment (r = relaxed, s = strict)
aspf	s	SPF alignment (r = relaxed, s = strict)

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.
!

No aggregate reports (rua)

DMARC record has no rua tag, so you receive no aggregate reports about who sends mail as your domain. Add rua=mailto:...

#19
✓ 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: mail

Found

Selectors: mail
_domainkey: NOERROR

Selector	Key	Flags
mail	RSA 1024 bits

Checks

✓ Keys found: mail #7

DKIM keys found for this domain with selectors: mail
!

1024-bit DKIM key

1024-bit RSA keys are the minimum and are considered weak today: mail (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 (2)
DS at parent: Yes
Algorithms: ECDSAP256SHA256 (13)
Key tags: 64667, 64184
Signatures valid until: 29 October 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 2026-10-29 #21

DNSKEY signatures are valid until 2026-10-29T00:00:00Z.

MX

warn

1 mail server

Found

Priority	Host	Records	Reverse DNS
0	mail.do.de	A 95.128.200.169 AAAA 2a00:1200:0:8::a48	mail.do.de ✓ mail.do.de ✓

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 2 MX addresss have a PTR record that resolves back to them.

TLS

warn

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

Found

MTA-STS record: v=STSv1; id=20260818081322Z;
Policy URL: https://mta-sts.do.de/.well-known/mta-sts.txt
Mode: enforce
Allowed MX: mail.do.de
Max age: 86400 seconds

DANE (TLSA records)

MX host	TLSA	DNSSEC
mail.do.de	3 1 1 cfb4aa0178960bb9…	Yes

Checks

✓ Record published #32

MTA-STS record found with id 20260818081322Z.
✓ Policy enforced #33

The MTA-STS policy is enforced and cached for 24h0m0s.
✓ All MX hosts covered #34

Every MX host matches an mx: line of the MTA-STS policy.
!

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://cdn.do.de/wp-content/uploads/bimi/bimi.svg

Found

Record: v=BIMI1;l=https://cdn.do.de/wp-content/uploads/bimi/bimi.svg
Found at: default._bimi.do.de
Logo: https://cdn.do.de/wp-content/uploads/bimi/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.