gn-online.de

Checked 21 October 2026, 22:40 UTC · via 8.8.8.8
✗Problems found
22 passed 4 warnings 1 failed 3 info

SPF

pass

SPF record published

Found

Record
v=spf1 mx include:ispgateway.de include:spf.protection.outlook.com include:spf.sendinblue.com ip4:154.45.40.130 ip4:54.170.167.63 ip4:85.214.122.223 ip4:82.165.72.65 ip4:82.165.163.234 ip4:87.106.168.102 ip4:217.160.70.231 ip4:194.195.3.64/27 -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

fail

p=none (_dmarc.gn-online.de)

Found

Record
v=DMARC1; p=none; sp=none; rua=mailto:dmarc@mailinblue.com!10m; ruf=mailto:dmarc@mailinblue.com!10m; rf=afrf; pct=100; ri=86400
Found at
_dmarc.gn-online.de
External report address
mailto:dmarc@mailinblue.com!10m (authorized)
TagValueMeaning
vDMARC1Version
pnonePolicy
spnoneSubdomain policy
pct100Percentage of mail the policy applies to
ruamailto:dmarc@mailinblue.com!10mAggregate report addresses
rufmailto:dmarc@mailinblue.com!10mFailure report addresses
rfafrfFailure report format
ri86400Report 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@mailinblue.com!10m
  • ✓ External report addresses authorized #29
    Report addresses in other domains have published their authorization.

DKIM

warn

Selectors: mail, selector1, selector2, s1, s2

Found

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

Checks

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

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

2 mail servers

Found

PriorityHostRecordsReverse DNS
0gnonline-de0e.mail.protection.outlook.comA 52.101.68.21 A 52.101.68.15 A 52.101.103.39 A 52.101.103.162 AAAA 2a01:111:f403:ca04::4 AAAA 2a01:111:f403:ca09::28 AAAA 2a01:111:f403:ca21::8 AAAA 2a01:111:f403:ca48::10mail-db4pr02cu00205.inbound.protection.outlook.com ✓ mail-db6pr03cu00107.inbound.protection.outlook.com ✓ mail-miypr05cu00207.inbound.protection.outlook.com ✓ mail-miypr03cu00202.inbound.protection.outlook.com ✓ mail-db4pr02cu00204.inbound.protection.outlook.com ✓ mail-am6pr02cu00300.inbound.protection.outlook.com ✓ mail-matpr04cu00100.inbound.protection.outlook.com ✓ mail-miypr05cu00100.inbound.protection.outlook.com ✓
100mxlb.ispgateway.deA 80.67.18.126mxlb.ispgateway.de ✓

Checks

  • ✓ 2 MX records #9
    Found 2 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: mxlb.ispgateway.de
    #11
  • ✓ Redundant MX hosts #12
    Found 2 MX records, which provides redundancy for email delivery.
  • ✓ At most 5 MX records #13
    Found 2 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 9 MX addresss have a PTR record that resolves back to them.

TLS

warn

no MTA-STS · no TLS-RPT · DANE on 0 of 2 MX hosts

Found

DANE (TLSA records)

MX hostTLSADNSSEC
gnonline-de0e.mail.protection.outlook.comnone-
mxlb.ispgateway.denone-

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