If Outlook has suddenly stopped receiving emails, you are not alone — it is one of the most common issues Outlook users encounter. The good news is that the cause is almost always something straightforward: a misconfigured rule, a full mailbox, a connectivity glitch, or a simple setting that has been changed accidentally. This guide walks through every fix methodically, from the quickest checks to the more involved solutions.
Is the Problem Outlook or Your Email Server?
Before diving into Outlook-specific fixes, the first thing to do is rule out a server-side issue. Open a web browser and log in to Outlook Web Access (OWA) at outlook.office.com (Microsoft 365) or your organisation’s webmail address. If new emails are arriving there but not in the Outlook desktop app, the problem is with the client. If webmail is also empty of new messages, the issue lies with your email server, your account, or possibly the sender — and you may need to involve your IT administrator or hosting provider.
Once you have confirmed new mail is reaching the server, work through the fixes below in order.
Fix 1: Check the Junk Email Folder
Outlook’s spam filter can be overzealous. Before assuming emails are missing, check your Junk Email folder — messages from legitimate senders often land there, especially if you have recently adjusted your junk mail settings or the sender is new. If you find a message in Junk that should not be there, right-click it, select Junk > Not Junk, and Outlook will move it to your inbox and remember the sender going forward.
Fix 2: Check Your Outlook Rules
Rules are one of the most common reasons emails appear to go missing. A rule can silently move, delete, or redirect incoming messages without you realising. To review your rules, go to File > Manage Rules & Alerts and look for any rules that apply to incoming mail — pay attention to rules that move messages to a folder, delete them, or forward them to another address. Disable or delete any rules that look suspicious. For a deeper look at why rules stop behaving as expected, see our guide on Outlook rules not working.
Fix 3: Turn Off Work Offline Mode
Outlook has a Work Offline mode that disconnects it from the mail server entirely — useful when you want to compose emails without distractions, but easy to switch on accidentally. If Outlook is in offline mode, it will not receive any new messages until you reconnect. Check the Send / Receive tab in the ribbon; if Work Offline is highlighted or active, click it once to disable it. You should see the status bar at the bottom of Outlook change from “Working Offline” to “Connected.”
Fix 4: Force a Send/Receive (F9)
Outlook should sync automatically at regular intervals, but sometimes the sync stalls or is delayed. Press F9 to force an immediate Send/Receive, or click Send / Receive All Folders in the Send / Receive tab. Watch the progress bar at the bottom of the screen. If Outlook throws an error during this process, it often points directly to the cause — for example, an authentication failure or a connection timeout — and gives you something specific to investigate.
Fix 5: Check Your Mailbox Storage Quota
Every mailbox has a storage limit, and when it is full, new emails are simply bounced back to senders. The sender typically receives a delivery failure notification, but you may never see those bounce messages if the mailbox is too full to accept them. To check your quota, go to File > Info and look at the account information panel — Outlook displays a mailbox size indicator there. If you are near or at the limit, archive older emails, empty your Deleted Items and Junk folders, or ask your administrator to increase your quota. You can also use File > Tools > Mailbox Cleanup to find and remove large or old items quickly.
Fix 6: Check the Blocked Senders List
If you are not receiving emails from a specific sender, they may have ended up on your blocked senders list — sometimes added accidentally. To check, go to Home > Junk > Junk Email Options and open the Blocked Senders tab. Scroll through the list to see if the sender’s email address or domain is listed. If it is, select it and click Remove. While you are there, also check the Safe Senders tab and make sure important contacts or domains are listed there to prevent future issues.
Fix 7: Check if Emails Are Being Sorted into a Subfolder
If rules or filters are active, incoming messages may be routed to a subfolder rather than your inbox — making them look like they have disappeared. Expand the folder list in the left panel of Outlook and look for any folders with unread counts. It is also worth checking the Focused and Other tabs if you use Microsoft 365’s Focused Inbox feature, as some messages are automatically sorted into the Other tab. You can switch off Focused Inbox under View > Show Focused Inbox if you prefer a single unified inbox.
Fix 8: Remove and Re-Add Your Email Account
If none of the above fixes have worked and Outlook still will not receive emails, removing the account and adding it back fresh often resolves deeper configuration corruption. Go to File > Account Settings > Account Settings, select your email account, and click Remove. Once removed, click New and follow the wizard to add the account again. For Microsoft 365 accounts, Outlook can usually auto-configure everything with just your email address and password. Note that if you need to import archived data after re-adding the account, see our guide on how to import a PST file into Outlook.
Fix 9: Check if the Sender’s Domain or IP Is Blacklisted (Admin-Level)
If a specific sender cannot get emails through to anyone in your organisation, the issue may be at the server level. Their sending domain or IP address could be listed on a public email blacklist (also known as a DNSBL or RBL), which causes your mail server to reject messages before they even reach Outlook. This is an admin-level task — your IT administrator can check public blacklist lookup tools such as MXToolbox to see if the sender’s IP is flagged. The sender’s IT team will need to request removal from any applicable blacklists. There is nothing you can do in Outlook itself to resolve this; the fix must happen at the server or sender level.
Additional Things to Check
- Outlook updates: An outdated version of Outlook can introduce sync bugs. Go to File > Office Account > Update Options > Update Now to make sure you are on the latest release.
- Antivirus email scanning: Some antivirus products intercept and scan incoming emails, which can cause delays or block delivery entirely. Try temporarily disabling email scanning in your antivirus and see if messages start arriving.
- Firewall or proxy: Corporate firewalls and proxy servers can occasionally block the ports Outlook uses (typically 993 for IMAP, 995 for POP3, or 443 for Exchange/HTTPS). Check with your network team if you suspect this is the case.
- Profile corruption: If the problem persists, your Outlook profile may be corrupted. You can create a new profile via Control Panel > Mail > Show Profiles and see if the issue disappears with a fresh profile.
Once you have restored normal email delivery, it is worth taking a moment to review your broader Outlook setup. Related guides you may find useful include our walkthrough on fixing Outlook search, how to set an out-of-office reply, and how to create an email signature in Outlook.
Frequently Asked Questions
Why has Outlook suddenly stopped receiving emails?
The most common causes are Work Offline mode being enabled, a sync error that requires a manual Send/Receive, a rule that is redirecting or deleting messages, or a full mailbox quota. Start by pressing F9 to force a sync and checking the Send / Receive tab for the Work Offline button.
Why am I not receiving emails from one specific person in Outlook?
Check your Blocked Senders list first — the sender’s address or domain may have been added there accidentally. Also check your Junk Email folder, and review any rules that apply to incoming messages. If no emails from that sender are reaching your server at all, the problem may be on their end (a blacklisted IP or a sending configuration issue).
How do I know if my Outlook mailbox is full?
Go to File > Info in Outlook — the account information section shows a mailbox size bar. If it is near the limit, you will need to archive or delete items. You can also use File > Tools > Mailbox Cleanup to find large messages and folders consuming the most space.
Should I use OWA to test if the problem is with Outlook or the server?
Yes — logging in to Outlook Web Access (outlook.office.com) is the fastest way to determine whether the issue is client-side or server-side. If mail is arriving in OWA but not in the desktop app, focus your troubleshooting on Outlook itself. If OWA is also showing no new messages, the problem is upstream of Outlook and will need server-level investigation.
