Using classic Outlook for Windows in business environments
Since sending works but inbox mail does not arrive while junk mail still does, focus on filtering and mailbox-side issues first.
- Check Outlook on the web.
- If new mail appears there, the problem is likely with Classic Outlook sync/profile.
- If new mail does not appear there either, the messages are likely being filtered, forwarded, deleted, or never reaching the mailbox.
- Check mailbox rules.
- In Outlook on the web, go to Settings > Mail > Rules.
- Make sure no rule is moving, deleting, or redirecting incoming mail.
- Check forwarding.
- In Outlook on the web, verify forwarding is turned off unless it is intentionally configured.
- Check Junk Email and Deleted Items.
- If valid messages are in Junk, move them back and mark them as not junk.
- Check message sorting and filters.
- In Outlook.com, restore the message list to chronological order with Filter > Sort > Date.
- Also check the Other tab if applicable.
- Check mailbox storage.
- If Microsoft cloud storage is full, mail cannot be sent or received, and messages sent during that time are bounced back and are unrecoverable.
- If this is only happening in Classic Outlook for Windows:
- Remove and re-add the account to force a resync.
- Rebuild the
.ostfile: close Outlook, open Run, enter%LOCALAPPDATA%\Microsoft\Outlook\, delete the file for the mailbox, then restart Outlook. This forces Outlook to download mailbox data again.
- If mail is missing in Outlook on the web too, ask the Microsoft 365 admin to run a message trace.
- This helps confirm whether messages reached Exchange Online or were blocked before delivery.
Because this is a business mailbox, if Outlook on the web also does not receive the missing messages after checking rules, forwarding, Junk, Deleted Items, and storage, the next step is admin investigation with message trace.
References:
- Can't send or receive email in Outlook.com
- I can send but i cannot receive new email - Microsoft Q&A I can send but i cannot receive new email
- Outlook.office.com can send emails but can't receive them - Microsoft Q&A I tried forwarding and that didn't work and I sent from google account and yahoo account as well my account account. Nothing works.