OTP emails disappear after a few seconds

Question

Since mid-May 2026, the OTP for a third-party website has disappeared from my business Outlook after a few seconds. I have checked the Junk folder and any other folders, as well as the quarantine folder. It's as if it never existed. It worked smoothly earlier. I have spoken to the third-party company, and they use the same process and email address. I also added that email address as a safe email address.

Some partners who are connected with that third-party company mentioned the same issue when I talked to them. The OTP emails disappear or look like they never existed. OTP emails sent before mid-May 2026 have also disappeared.

• No wrong rules
• No Archiving
• No conversation mode
• No email forwarding

It seems to be happening on the server side because I've checked it on the desktop app, the web browser, and the phone app.

Answer 1

Hi @P,

Based on your description, this does not sound like a problem with Outlook itself, since the behavior is the same in Outlook desktop, Outlook on the web, and mobile devices.

If the OTP messages briefly appear and then disappear, the most likely causes are:

• Exchange Online mail flow (transport) rules
• Microsoft Defender for Office 365 filtering
• Automated remediation actions (ZAP/AIR)
• A retention or compliance policy applied at the tenant level

Since you have already verified:

• No inbox rules
• No forwarding
• No archiving
• No conversation view issues
• No messages in Junk Email or Quarantine

the next step is for your Microsoft 365 administrator to run a Message Trace for one of the missing OTP messages. Message Trace can show whether the message was delivered, quarantined, deleted, or acted on by a mail flow rule or security policy. Microsoft documents this process here:

• Message Trace in Exchange Online
• Message Trace FAQ

The fact that other organizations using the same third-party service are reporting similar behavior may also indicate that the sender's messages are being affected by Microsoft 365 security filtering rather than anything specific to your mailbox. There have been cases where legitimate messages were incorrectly handled by Exchange Online filtering.

If you are not the Microsoft 365 administrator, I recommend contacting your tenant administrator and asking them to perform a Message Trace on a recent OTP email and review any Exchange Online or Defender policies that may be acting on those messages. Message Trace will usually reveal what happened to the message after it reached Microsoft 365.

Hope this will helps.

Answer 2

Based on the described behavior and the provided information, the most likely causes are:

1. A view/filter hiding the items
2. A rule or server-side process moving or deleting the items in a way that is not obvious
3. A broader service-side issue affecting multiple customers

From the available information, the only directly supported, concrete troubleshooting step is to verify that no folder view filter is hiding the OTP messages.

Follow these steps in classic Outlook (desktop) for the folder where the OTPs should arrive (usually Inbox):

1. Go to the View tab in the ribbon.
2. In Current View, select View Settings.
3. Select Filter….
4. Check each tab for any criteria that could hide messages:
   • Tasks
   • More Choices
   • Advanced
5. Clear or adjust any filters (for example, filters on date, read/unread, sender, importance, or size) and apply the changes.

If a filter was applied, removing it will make previously “disappeared” items visible again, provided they were only being filtered and not deleted.

If no filters are present and the issue affects multiple organizations with the same sender, this points to a service-side or sender-side issue that is not covered in the provided material. In that case, escalation through the organization’s Microsoft 365 support channel is required so that support can inspect server-side message trace and policies.

---

References:

• Items disappear or are not visible in an Outlook folder
• Can't send or receive email in Outlook.com
• Email is missing from your Outlook.com inbox
• Overview of the Junk Email Filter in classic Outlook
• Stopped receiving emails on my account. - Microsoft Q&A