ace-online.de

Checked 21 October 2026, 21:27 UTC · via 8.8.8.8
✗Problems found
20 passed 2 warnings 2 failed 2 info

SPF

pass

SPF record published

Found

Record
v=spf1 a:mail.ace.de ip4:87.234.225.28 include:spf.protection.outlook.com include:spf.dynect.net -all
DNS lookups
3 of 10
Void lookups
0 of 2

Checks

  • ✓ No deprecated ptr mechanism #1
    No ptr mechanism found in SPF record.
  • ✓ 3 of 10 DNS lookups #2
    SPF record needs 3 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

No DMARC record found

Checks

  • ✗
    No DMARC record
    No DMARC record was found for this domain. DMARC is essential for preventing email spoofing. Add a DMARC record with p=reject or at least p=quarantine.
    #5

DKIM

fail

No keys found under the checked selectors

Found

Selectors
None found
_domainkey
NXDOMAIN

Checks

  • ✗
    No DKIM keys published
    _domainkey.ace-online.de does not exist (NXDOMAIN), so no DKIM keys are published. DKIM helps prevent email spoofing. Configure DKIM with your email service provider.
    #7

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

1 mail server

Found

PriorityHostRecordsReverse DNS
10aceonline-de0i.mail.protection.outlook.comA 52.101.181.153 A 52.101.68.27 A 52.101.209.153 A 52.101.209.28 AAAA 2a01:111:f403:ca09::26 AAAA 2a01:111:f403:ca48::8 AAAA 2a01:111:f403:ca09::28 AAAA 2a01:111:f403:ca48::10mail-wa4pr04cu00101.inbound.protection.outlook.com ✓ mail-db7pr03cu00503.inbound.protection.outlook.com ✓ mail-cpjpr04cu00101.inbound.protection.outlook.com ✓ mail-cpjpr05cu00104.inbound.protection.outlook.com ✓ mail-am8pr83cu00106.inbound.protection.outlook.com ✓ mail-miypr02cu00100.inbound.protection.outlook.com ✓ mail-am6pr02cu00300.inbound.protection.outlook.com ✓ mail-miypr05cu00100.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

info

MTA-STS enforce · TLS-RPT · DANE on 0 of 1 MX hosts

Found

MTA-STS record
v=STSv1; id=20210707134000Z
Policy URL
https://mta-sts.ace-online.de/.well-known/mta-sts.txt
Mode
enforce
Allowed MX
aceonline-de0i.mail.protection.outlook.com
Max age
86400 seconds
TLS-RPT record
v=TLSRPTv1; rua=mailto:postmaster@ace.de

DANE (TLSA records)

MX hostTLSADNSSEC
aceonline-de0i.mail.protection.outlook.comnone-

Checks

  • ✓ Record published #32
    MTA-STS record found with id 20210707134000Z.
  • ✓ 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.
  • ✓ Reports enabled #35
    TLS reports are sent to: mailto:postmaster@ace.de
  • 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