Sources checked: 12 October 2026.
First work out whether Outlook.com is rejecting new mail or whether messages have arrived but are hidden from your inbox. A useful test is a short email with a unique subject sent from another address you control. Note the send time and any delivery error returned to that sender.
Check both storage limits
Open Outlook.com Settings > Account > Storage to inspect mailbox usage. Also check your Microsoft cloud storage. Microsoft explains that exceeding either allowance can stop Outlook.com from receiving email, even when the other allowance has space. Mail sent while storage is full is returned to the sender; it is not waiting in a queue for you to recover later.
Review large messages and OneDrive files before removing anything you need. Deleted Items still uses mailbox space until emptied or automatically cleared. Once space is available, ask the sender to resend. See Microsoft’s storage guidance for the current limits and cleanup controls.
Look for mail that already arrived
- Check Other if Focused Inbox is on, set the message-list filter to All, and search for the test subject.
- Open Junk Email. For a legitimate message, use Mark as not junk.
- Check blocked senders for an address or whole domain that was added by mistake. Avoid removing all filtering safeguards.
- Review message-moving rules and Archive if the search finds the message outside Inbox.
Microsoft’s receiving-email checklist distinguishes filtering and account problems. Its missing-message guide covers rules and alternate folders.
Inspect forwarding
If you intentionally forward mail, open Settings > Mail > Forwarding and check the destination and Keep a copy of forwarded messages setting. Remove unintended forwarding and save. Microsoft documents these forwarding controls. An address you do not recognize may require a separate account-security review.
Use the sender’s delivery evidence
For one sender only, ask whether they received a non-delivery report and its error code. For all senders, compare Outlook.com webmail with your email app; an app-only failure needs an app/sync check. Avoid changing multiple settings at once so you can identify the cause.
If you can sign in and still need help, use Outlook.com’s Help pane as described in Microsoft’s official support instructions. Include the test time and delivery behavior, keeping message contents and private account details out of public posts.
Independent information: Number Customer Care is not affiliated with Microsoft. We cannot access your account, reset your password or provide Microsoft customer support.