bild.de

bild.de · Last checked 2026-10-04 02:16 UTC

bild.de

Good, with 3 things to fix

bild.de scored 76/100 (grade B). The main issues are DKIM key shorter than 2048 bits and DMARC: subdomain policy is weaker than the domain policy, plus 1 more. Detected senders: Microsoft 365.

Checked 2026-10-04 02:16 UTC · fresh check

1 passed3 need attention0 failing4 for informationDetected senders: Microsoft 365
Fix this firstThe change with the biggest effect

Strengthen the DMARC policy

Rejects mail that fails DMARC, the strongest protection against spoofing. Changes: Subdomains move one step, from sp=none to sp=quarantine.

TypeTXT
Name / Host
_dmarc.bild.de

Some DNS providers want just “_dmarc” here.

Value
v=DMARC1; p=reject; sp=quarantine; rua=mailto:dmarc-rua@dkim10888.de; adkim=r; aspf=r
Replaces
v=DMARC1; p=reject; sp=none; rua=mailto:dmarc-rua@dkim10888.de; ruf=mailto:dmarc-ruf@dkim10888.de

How to apply it

  1. Sign in where your domain’s DNS is managed. This is often where you bought the domain, such as Cloudflare, GoDaddy or Namecheap.
  2. Find the existing TXT record with that name and replace its value.
  3. Save, then come back and re-check. DNS changes can take up to a few hours to show.

All checks

MXCan servers find your inbox?Only one MX hostInfo
  • Info: Only one MX host

    All mail for bild.de goes to bild-de.mail.protection.outlook.com. Most hosted providers make that one name highly available; if you run your own server, consider a backup MX.

SPFWho may send as you?SPF ends in neutral (?all)Needs attention
  • Warning: SPF ends in neutral (?all)

    "?all" tells receivers to treat mail from unlisted servers as neither pass nor fail, so SPF gives no protection. End the record with "-all" or "~all".

DKIMAre your emails signed?DKIM key shorter than 2048 bitsNeeds attention
  • Warning: DKIM key shorter than 2048 bits

    selector1 (1024-bit) uses an RSA key below 2048 bits. Short keys can be factored and some receivers treat them as weak. Rotate to a 2048-bit key at your sending provider.

  • Pass: DKIM key published

    bild.de publishes a DKIM key under selector1.

DMARCWhat happens to fakes?Subdomain policy is weaker than the domain policyNeeds attention
  • Warning: Subdomain policy is weaker than the domain policy

    sp=none is weaker than p=reject, so attackers can spoof any subdomain of bild.de (for example billing.bild.de) even though the main domain is protected.

    How to fix this
AlignmentDoes it match your From?No issues foundPass

Nothing to report.

BIMICan inboxes show your logo?No BIMI recordInfo
  • Info: No BIMI record

    No BIMI record at default._bimi.bild.de. BIMI is optional: it shows your logo next to your mail in supporting inboxes once DMARC is enforced.

    How to fix this
MTA-STSIs mail to you encrypted?No MTA-STS recordInfo
  • Info: No MTA-STS record

    No MTA-STS record at _mta-sts.bild.de. MTA-STS (RFC 8461) makes sending servers require TLS and a valid certificate when delivering to you, which blocks downgrade attacks.

    How to fix this
TLS-RPTWill you hear about failures?No TLS-RPT recordInfo
  • Info: No TLS-RPT record

    No TLS reporting record at _smtp._tls.bild.de. TLS-RPT (RFC 8460) tells senders where to send daily reports about failed encrypted deliveries to you.

    How to fix this

Other fixes

Publish the MTA-STS recordTXT

Tells sending servers that bild.de publishes an MTA-STS policy at https://mta-sts.bild.de/.well-known/mta-sts.txt. Change the id whenever the policy file changes.

TypeTXT
Name / Host
_mta-sts.bild.de

Some DNS providers want just “_mta-sts” here.

Value
v=STSv1; id=202610040216

Host the MTA-STS policy filepolicy-file

Serve this file over HTTPS with a valid certificate for mta-sts.bild.de. It lists your MX hosts and starts in testing mode; switch to mode: enforce once TLS-RPT reports show no failures.

Location
https://mta-sts.bild.de/.well-known/mta-sts.txt
Contents
version: STSv1
mode: testing
mx: bild-de.mail.protection.outlook.com
max_age: 604800

Set up a TLS report addressinstruction

Sending servers will report TLS failures when delivering to bild.de, which you need before enforcing MTA-STS. The address must accept TLS reports; a DMARC report address does not necessarily do so.

Applies to: _smtp._tls.bild.de

  1. Pick an address that will receive TLS reports: a mailbox you read (for example tls-reports@bild.de, created first) or a TLS reporting service. 2. Publish a TXT record at _smtp._tls.bild.de with the value v=TLSRPTv1; rua=mailto:<that address>.

Prepare BIMIinstruction

BIMI shows your logo next to messages in supporting inboxes, but only for mail that passes DMARC under an enforced policy.

Applies to: default._bimi.bild.de

  1. Enforce DMARC first: p=quarantine or p=reject at 100% (no pct below 100). 2. Convert your logo to an SVG Tiny PS file and host it over HTTPS, for example https://bild.de/bimi/logo.svg. 3. For Gmail and Apple Mail, obtain a VMC or CMC certificate for the logo. 4. Publish a TXT record at default._bimi.bild.de with v=BIMI1, l= set to the logo URL and a= set to the certificate URL.