emails sent Nov.11, 2026

For Outlook.com messages already sent without delivery receipts, check Sent Items and search for non-delivery reports; Outlook.com does not provide a retrospective per-message delivery trace that proves every message reached its destination.

Check the November 11 messages

1. Open Outlook.com → Sent Items and filter or scroll to November 11, 2026.
   • A message in Sent Items indicates that Outlook accepted the send action; it does not prove delivery to every recipient.
   • Check Drafts and Deleted Items for messages that never completed sending.
2. Search all folders, including Junk Email, for failure notices. Search for terms such as:
   • undeliverable
   • delivery failed
   • couldn't be delivered
   • returned mail
   • postmaster
   • mailer-daemon
   Open each non-delivery report (NDR or “bounce”) and note the affected recipient and error. Common reports identify an invalid address, full mailbox, receiving-server problem, spam rejection, or oversized message.^1^
3. For messages with no NDR, ask a representative sample of recipients to check Inbox and Junk/Spam.
   • Include recipients using different providers, such as Outlook.com, Gmail, Yahoo, and organizational mail.
   • Ask them to search by your address, subject, and approximate sending time.
   • No NDR is not conclusive proof of delivery: the recipient’s system could have filtered the message without returning a useful notice.
4. Do not resend all 100 messages immediately. Resend only confirmed missing messages, preferably in smaller groups. Outlook.com applies daily, per-message, and “non-relationship recipient” limits, and actual limits can vary with account usage history.^2^

About the reported outage

The available public reporting places the widespread Outlook/Microsoft 365 disruption on November 12, 2026, rather than November 11.^3^ Check Microsoft’s public service-health page for current or published incident information.^4^

That record alone cannot determine which of your individual messages failed. The NDRs and recipient confirmations are the useful evidence for an Outlook.com personal account.

Why receipts cannot be added afterward

Delivery and read receipts must be requested before sending. A delivery receipt reports delivery to the recipient’s mailbox, while a read receipt reports that the message was opened; recipients or their email systems may decline or not support read receipts.^5^

Outlook.com on the web cannot request read receipts. For future important messages sent through Outlook for Windows, enable them while composing under Options → Tracking → Request a Delivery Receipt or Request a Read Receipt.^6^

If this is actually a work or school mailbox

Ask the Microsoft 365 administrator to run a Message Trace using the sender, recipients, and approximate send times. That administrative facility can show whether messages were delivered, rejected, quarantined, filtered, or redirected. It is not available as equivalent retrospective tracking for a personal Outlook.com mailbox.^7^

If many messages are absent from Sent Items, or numerous NDRs indicate an account-level restriction rather than recipient-specific failures, use Help in Outlook.com, enter the issue, complete the self-help prompts, and select Still need help? → Yes to contact Outlook.com support.^1^

References

1. Can't send or receive email in Outlook.com | Microsoft Support
2. Sending limits in Outlook.com | Microsoft Support
3. Widespread Microsoft outage takes down Outlook and other 365 ... - CNBC
4. Microsoft service health status
5. Customize your email message | Microsoft Support
6. [Classic Outlook](https://support.microsoft.com/outlook/mail/add-and-request-read-receipts-and-delivery-notifications-in-outlook)
7. some emails not being delivered to our Inboxes - Microsoft Q&A