Mastercard emails with pin for validation are not arriving, either on inbox, spam or quarantine mode

A Microsoft 365 administrator should run an Exchange Online message trace for an affected user and PIN request, because this determines whether Mastercard’s message reached Microsoft 365, was filtered, or was delivered but not displayed in New Outlook.

Run a targeted message trace

Since Inbox, Junk, and Quarantine have already been checked, do not repeat those checks.

1. Have one affected user request a new Mastercard PIN and record:
   • Exact request time and time zone.
   • Recipient address.
   • Expected Mastercard sender address or domain, if known.
2. Wait approximately 10 minutes; trace data can take up to an hour to appear.
3. Sign in with an Exchange Administrator or Organization Management account. Microsoft recommends using the least-privileged suitable role rather than Global Administrator.
4. Open Exchange admin center → Mail flow → Message trace → Start a trace.
5. Set:
   • Recipients: the affected user.
   • Senders: Mastercard’s exact sending address or domain if known; otherwise leave this unrestricted.
   • Time range: narrowly cover the PIN request.
   • Optionally, use a subject filter such as “PIN,” “verification,” or text supplied by Mastercard.
6. Select Search, open the matching result, and review its status and event details. Message trace can show whether Exchange Online received, rejected, deferred, filtered, quarantined, or delivered the message.^1^

Act on the trace result

• No matching message: Exchange Online did not record the message for that recipient and period. Ask Mastercard support to confirm:
  • The PIN email was actually generated.
  • The exact destination address.
  • The envelope sender and sending domain.
  • The send timestamp, Message-ID, and any SMTP rejection or non-delivery response.
  Run another trace with those exact details. A message that was never sent is one documented explanation for a missing traceable delivery.^2^
• Failed or Filtered as spam: Open the trace details and note the SMTP response, policy, rule, or filtering event. Follow the How to fix it information shown for that event. Do not broadly allow-list a domain until the exact authenticated Mastercard sender has been confirmed.
• Quarantined: The trace proves the message entered Microsoft 365 and identifies the filtering action. An administrator should use the trace details to identify the applicable policy before releasing or allowing future messages.
• Pending or Getting status: Delivery is still being attempted or its status has not finished processing. Check the same trace again later.
• Delivered: Exchange Online delivered the message to the mailbox. Open that mailbox in Outlook on the web:
  • If the message appears there but not in New Outlook, the problem is client-side synchronization or display.
  • If it does not appear there, inspect Settings → Mail → Rules and Forwarding, plus Deleted Items, Archive, Other, and custom folders. A delivered message can subsequently be redirected or deleted by a mailbox rule.^2^

Outlook on the web is the appropriate comparison because receiving there but not in the installed application isolates the issue to the computer or email client.^3^

Escalation information

If several PIN attempts produce no trace results while other Mastercard emails arrive, provide Mastercard with the affected timestamps and recipient addresses through a private support channel. If the trace shows rejection or filtering, provide Microsoft 365 support with the trace details, Network Message ID, SMTP status, sender, recipient, and timestamp—without posting addresses or PINs publicly.

Windows 11 itself is unlikely to determine whether the message reaches Exchange Online; the Outlook-on-the-web comparison and message trace establish whether this is a New Outlook display issue, Microsoft 365 mail-flow action, or sender-side failure.

References

1. Message trace in the Exchange admin center in Exchange Online
2. Message Trace FAQ in Exchange Online
3. Find and fix email delivery issues as a Microsoft 365 for business admin