Please note that our forum is a public platform, and we will modify your question to hide your personal information in the description. Kindly ensure that you hide any personal or organizational information the next time you post an error or other details to protect personal data.
Hello TIM C
Thank you for reaching out to the Microsoft Q&A Forum. I understand it’s frustrating when emails keep reappearing even after you delete or move them.
Just to confirm, do those two emails also reappear when you delete them in Outlook on the web, or is the issue only happening on the iPhone Outlook app?
Here's what you can try next:
1. Delete the messages from Outlook on the web instead of from the Outlook app
- Sign in to Outlook on the web and locate the two messages.
- Delete them there, then check Deleted Items folder (and empty it if needed).
2. Prevent more emails from that sender
Since these are from the same sender/domain, you can block the sender/domain so future messages go to Junk instead of Inbox.
- Still in Outlook on the web, go to Settings > Mail > Junk email
- Add that sender address/ domain to Blocked senders and domains
- Save changes
You can also see this guide: Block or unblock senders in Outlook - Microsoft Support
3. Force-close Outlook mobile app and retry the sign-in
- On your phone, swipe up to the app switcher > swipe Outlook away > reopen Outlook.
- Go to your phone's Settings > Ensure iOS Mail or Outlook app has Background App Refresh enabled.
For more details, you can see: Failed delivery messages from the postmaster at outlook.com, microsoft.com, or service.microsoft.com - Microsoft Support
Please feel free to let me know how it goes after trying these steps so I can guide you further. Thank you so much for your understanding.
If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.