Mail domain report: rtl.de

SPF

pass

SPF record published

Found

Record: v=spf1 a mx ip4:217.118.170.10 ip4:193.16.163.0/24 include:mail.zendesk.com include:spf.mailjet.com include:spf.crsend.com include:_spf.zimpel.de ip4:185.41.28.0/22 ip4:94.143.16.0/21 ip4:185.24.144.0/22 ip4:153.92.224.0/19 ip4:213.32.128.0/18 ip4:185.107.232.0/22 ip4:77.32.128.0/18 ip4:77.32.192.0/19 ip4:212.146.192.0/18 ip4:172.246.0.0/18 ip4:34.215.113.156 include:_spf.salesforce.com include:143803951.spf10.hubspotemail.net 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

fail

p=none (_dmarc.rtl.de)

Found

Record: v=DMARC1; p=none; rua=mailto:dmarc@cbc.de,mailto:dmarc@mailinblue.com,mailto:rua@dmarc.brevo.com; ruf=mailto:dmarc@cbc.de,mailto:dmarc@mailinblue.com; adkim=r; aspf=r; rf=afrf; pct=100; ri=86400
Found at: _dmarc.rtl.de
External report address: mailto:dmarc@cbc.de (authorized)
External report address: mailto:dmarc@mailinblue.com (authorized)
External report address: mailto:rua@dmarc.brevo.com (authorized)

Tag	Value	Meaning
v	DMARC1	Version
p	none	Policy
pct	100	Percentage of mail the policy applies to
rua	mailto:dmarc@cbc.de,mailto:dmarc@mailinblue.com,mailto:rua@dmarc.brevo.com	Aggregate report addresses
ruf	mailto:dmarc@cbc.de,mailto:dmarc@mailinblue.com	Failure report addresses
adkim	r	DKIM alignment (r = relaxed, s = strict)
aspf	r	SPF alignment (r = relaxed, s = strict)
rf	afrf	Failure report format
ri	86400	Report interval (seconds)

Checks

✗

Policy: none (monitoring only)

DMARC policy is set to 'none', which only monitors but doesn't protect against spoofing. Consider upgrading to 'quarantine' or ideally 'reject'.

#4
✓ Record published #5

DMARC record exists for this domain.
✓ Valid syntax #17

DMARC record syntax is valid.
✓ Aggregate reports enabled #19

Aggregate reports are sent to: mailto:dmarc@cbc.de, mailto:dmarc@mailinblue.com, mailto:rua@dmarc.brevo.com
✓ 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

warn

Not signed

Found

DNSKEY records: No (0)
DS at parent: No

Checks

!

Not enabled

DNSSEC is not enabled for this domain. Consider enabling DNSSEC to protect against DNS spoofing attacks.

#8

MX

warn

4 mail servers

Found

Priority	Host	Records	Reverse DNS
10	assur.rtl.de	A 193.16.163.11	assur.rtl.de ✓
10	marduk.rtl.de	A 193.16.163.31	marduk.rtl.de ✓
20	sul.rtl.de	A 193.16.163.16	sul.rtl.de ✓
20	sulis.rtl.de	A 193.16.163.17	sulis.rtl.de ✓

Checks

✓ 4 MX records #9

Found 4 MX records for this domain.
✓ All hosts resolve #10

All MX records resolve to valid IP addresses.
!

Hosts without IPv6

The following MX hosts could not be resolved to IPv6 addresses: assur.rtl.de, marduk.rtl.de, sul.rtl.de, sulis.rtl.de

#11
✓ Redundant MX hosts #12

Found 4 MX records, which provides redundancy for email delivery.
✓ At most 5 MX records #13

Found 4 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 4 MX addresss have a PTR record that resolves back to them.

TLS

warn

no MTA-STS · no TLS-RPT · DANE on 0 of 4 MX hosts

Found

DANE (TLSA records)

MX host	TLSA	DNSSEC
assur.rtl.de	none	-
marduk.rtl.de	none	-
sul.rtl.de	none	-
sulis.rtl.de	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

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