First sign in to Outlook on the web. If the emails are there, the problem is the Outlook app on your computer. If they're missing there too, check Junk, rules, and quarantine, and confirm the mailbox isn't full.
Common causes
Outlook is offline
Work Offline mode or a disconnected Outlook stops new mail from arriving on the computer.
Junk or Other folder
Messages land in Junk or the "Other" tab of Focused Inbox.
Rules moving messages
An inbox rule — sometimes created by an attacker — moves or deletes incoming mail.
Quarantine or filtering
Microsoft 365 or a security service may be holding messages.
Mailbox full
A full mailbox rejects new messages.
How to fix it, step by step
- 1
Check Outlook on the web
Sign in at outlook.office.com. If mail is there, focus on the desktop app.
- 2
Turn off Work Offline
In Outlook's Send/Receive tab, make sure Work Offline isn't highlighted.
- 3
Check Junk, Other, and rules
Look in Junk and the Other tab, then review rules under Settings > Mail > Rules.
- 4
Check quarantine
Your administrator can check Microsoft 365 quarantine and message trace for missing emails.
- 5
Check mailbox size
In File > Info (classic Outlook), check how much space is left.
When to call a technician
If you find rules you didn't create, treat it as a possible account compromise and call right away. We can run a message trace to see exactly what happened to missing emails.
On-site support across Orange County · see our IT support, managed IT, Microsoft 365 support and cybersecurity services.
Frequently asked questions
Why do I get some emails but not others?
Specific messages may be going to Junk, being caught by filtering, or moved by a rule.
What is message trace?
A Microsoft 365 admin tool that shows whether a message reached your organization and what happened to it.
Could a hacker hide my emails?
Yes. Attackers often create rules that hide or forward messages. Check for rules you didn't make.