transsion-os.com

transsion-os.com · Last checked 2026-10-04 02:20 UTC

transsion-os.com

Needs work, with 2 things to fix

transsion-os.com scored 65/100 (grade C). The main issues are DMARC policy is none and no DKIM key found for the common selectors, plus 1 more. Detected senders: Microsoft 365.

Checked 2026-10-04 02:20 UTC · fresh check

2 passed2 need attention0 failing4 for informationDetected senders: Microsoft 365
Fix this firstThe change with the biggest effect

Strengthen the DMARC policy

Quarantines 25% of mail that fails DMARC, a safe first step: check the reports for legitimate senders that fail before going further. There is no report address yet: set one up first (see the DMARC reporting fix) so you can confirm your legitimate mail passes before enforcing.

TypeTXT
Name / Host
_dmarc.transsion-os.com

Some DNS providers want just “_dmarc” here.

Value
v=DMARC1; p=quarantine; pct=25; adkim=r; aspf=r
Replaces
v=DMARC1; p=none;

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 transsion-os.com goes to transsionos-com02c.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?No issues foundPass

Nothing to report.

DKIMAre your emails signed?No DKIM key found for the common selectorsNeeds attention
  • Warning: No DKIM key found for the common selectors

    None of the 47 selectors probed under transsion-os.com publish a DKIM key. DNS cannot list selectors, so a key under a custom selector may exist: find the s= value in the DKIM-Signature header of a message you sent and check that selector. If DKIM is not set up, enable it at each service that sends mail for transsion-os.com.

DMARCWhat happens to fakes?DMARC policy is noneNeeds attention
  • Warning: DMARC policy is none

    A none policy only monitors: mail that fails DMARC is still delivered, so anyone can spoof the domain. Once reports show your legitimate senders pass, move to quarantine and then reject.

    How to fix this
  • Warning: No DMARC aggregate report address

    Without a rua address you receive no aggregate reports, so you cannot see who sends as your domain or safely tighten the policy.

    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.transsion-os.com. 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.transsion-os.com. 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.transsion-os.com. TLS-RPT (RFC 8460) tells senders where to send daily reports about failed encrypted deliveries to you.

    How to fix this

Other fixes

Set up a DMARC report addressinstruction

Without a rua address nobody receives aggregate reports, so you cannot see who sends as transsion-os.com or tell when it is safe to tighten the policy. Adding reporting does not change how receivers treat your mail.

Applies to: _dmarc.transsion-os.com

  1. Get an address that collects DMARC aggregate reports: add transsion-os.com to MailVakt to receive one, or sign up with any DMARC report service. 2. Edit the TXT record at _dmarc.transsion-os.com and add rua=mailto:<that address>, keeping every other tag (p=none) as it is. 3. A report service on another domain must authorize transsion-os.com; most publish that record for you.

Enable DKIM for Microsoft 365instruction

Microsoft 365 generates the DKIM key for each account, so the exact record must come from Microsoft 365. Without DKIM, mail it sends for transsion-os.com cannot pass DMARC through DKIM.

Applies to: selector1._domainkey.transsion-os.com

  1. In Microsoft 365, enable DKIM signing for transsion-os.com: tenant-specific: copy Selector1CNAME/Selector2CNAME from Microsoft 365 Defender > Email authentication > DKIM. Publish exactly the record Microsoft 365 shows (TXT or CNAME) at the host name it gives, then turn signing on. Instructions: https://learn.microsoft.com/microsoft-365/security/office-365-security/email-authentication-dkim-configure

Enable DKIM for Microsoft 365instruction

Microsoft 365 generates the DKIM key for each account, so the exact record must come from Microsoft 365. Without DKIM, mail it sends for transsion-os.com cannot pass DMARC through DKIM.

Applies to: selector2._domainkey.transsion-os.com

  1. In Microsoft 365, enable DKIM signing for transsion-os.com: tenant-specific: copy Selector1CNAME/Selector2CNAME from Microsoft 365 Defender > Email authentication > DKIM. Publish exactly the record Microsoft 365 shows (TXT or CNAME) at the host name it gives, then turn signing on. Instructions: https://learn.microsoft.com/microsoft-365/security/office-365-security/email-authentication-dkim-configure

Publish the MTA-STS recordTXT

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

TypeTXT
Name / Host
_mta-sts.transsion-os.com

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

Value
v=STSv1; id=202610040220

Host the MTA-STS policy filepolicy-file

Serve this file over HTTPS with a valid certificate for mta-sts.transsion-os.com. 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.transsion-os.com/.well-known/mta-sts.txt
Contents
version: STSv1
mode: testing
mx: transsionos-com02c.mail.protection.outlook.com
max_age: 604800

Set up a TLS report addressinstruction

Sending servers will report TLS failures when delivering to transsion-os.com, 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.transsion-os.com

  1. Pick an address that will receive TLS reports: a mailbox you read (for example tls-reports@transsion-os.com, created first) or a TLS reporting service. 2. Publish a TXT record at _smtp._tls.transsion-os.com 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.transsion-os.com

  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://transsion-os.com/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.transsion-os.com with v=BIMI1, l= set to the logo URL and a= set to the certificate URL.