not receiving emails from certain people all of the sudden

Dear @Jim Lilly,

Thank you for posting your question in the Microsoft Q&A forum. I understand that since last Wednesday, emails from some clients stopped arriving even though you were previously in active conversations with them. Other emails work fine, and you’ve already checked connectivity and confirmed your domain isn’t blacklisted.

Typically, this issue often happens due to:

Messages being moved or hidden by rules, Focused Inbox, or filters (Junk, Deleted Items, Archive).

Security filtering placing emails in Quarantine because of spam or spoof checks.

Organization mail‑flow changes or sender authentication issues (SPF/DKIM/DMARC).

To better assistance, could you please confirm following information:

• Do those senders see a bounce/NDR message? If yes, please share the error code and text.
• Have you checked Junk, Deleted Items, Archive, and the Other tab (Focused Inbox)?
• Any Inbox rules or filters changed recently?
• Did you or your admin check if these emails are in Quarantine?

In the meantime, I recommend some steps below:

1/ Search all folders in Outlook on the web

• Sign in to Outlook on the web at https://outlook.office.com.
• In the Search bar at the top, type: from:******@domain.com (Replace ******@domain.com with the actual email address.)
• Press Enter and select All folders in the search scope to ensure results include Inbox, Junk, Archive, and subfolders.

2/ Turn off Focused Inbox temporarily

• In Outlook on the web, click the Settings in the top-right corner.
• Select Mail > Layout > Focused Inbox.
• Choose Don’t sort messages or toggle Focused Inbox to Off.
  

This ensures all messages appear in a single view instead of being split into “Focused” and “Other.”

3/ Review and disable Inbox rules

• Go to Settings > Mail > Rules.
• Review the list of rules. If any rule moves or deletes messages from the affected senders, disable or delete it.
• Save changes and test by asking the sender to resend an email.

4/ Add affected addresses/domains to Safe senders and remove from Blocked senders

• In Outlook on the web, go to Settings > Mail > Junk email.
• Under Safe senders and domains, click Add and enter the sender’s email address or domain.
• Under Blocked senders and domains, check if the sender/domain is listed. If yes, remove it.
• Save changes.
  

5/ Ask the sender to resend a simple test email

Request the sender to send a new email with:

A short subject line.

• No attachments, links, or images

This helps rule out filtering caused by content or formatting.

Please understand that our initial response does not always resolve the issue immediately. However, with your help and more detailed information, we can work together to find a solution.

I truly appreciate your patience and understanding. If you have any further questions or need further clarification, please feel free to reach out. I'm looking forward to hearing from you. 

Thank you for your cooperation.

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