How to Fix Outlook Not Sending or Receiving Emails

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How to Fix Outlook Not Sending or Receiving Emails

Microsoft Outlook is one of the most widely used email applications for businesses. When Outlook stops sending or receiving emails, productivity can come to a halt. Fortunately, most Outlook email issues can be resolved with a few troubleshooting steps.

Which Outlook do you have? These steps are for classic Outlook for Windows (the one with File and Send / Receive tabs). The new Outlook for Windows and Outlook on the web don't use PST files, profiles or Safe Mode; for those, check Steps 1, 3 and 4 and try signing in at outlook.com or outlook.office.com - if mail works there, the problem is the app on your PC.

Common Symptoms

Emails remain in the Outbox.
New emails are not received.
Outlook displays Send/Receive errors.
Outlook keeps asking for a password.
Synchronization errors occur.

Step 1: Check Internet Connectivity

Before troubleshooting Outlook, verify that your internet connection is working properly. Open a web browser and visit several websites. If the websites do not load, resolve the network issue first - for example with our guides to DNS server not responding or Ethernet connected but no internet.

Step 2: Verify Outlook is Online

Open Outlook and check the status bar. If it shows "Working Offline," click the Send/Receive tab and disable Work Offline mode.

Step 3: Check Mailbox Storage

A full mailbox can prevent emails from being sent or received. Review mailbox usage (File > Info shows Mailbox Settings and the space used for Microsoft 365 and Exchange accounts) and remove unnecessary messages or archive older emails. Empty Deleted Items afterwards - deleted mail still counts until it is emptied.

Also check the Outbox: a message with a very large attachment can block everything behind it. Move it to Drafts, remove or shrink the attachment, and send again.

Step 4: Verify Account Credentials

Incorrect passwords can interrupt synchronization.

Open Account Settings.
Select the affected account.
Update the password if necessary.
Test the account settings.

Step 5: Repair Outlook Data Files

Corrupted PST or OST files can cause email issues.

Close Outlook.
Run Microsoft's Inbox Repair Tool (SCANPST.EXE). It is in your Office installation folder - for Microsoft 365 usually C:\Program Files\Microsoft Office\root\Office16.
Select the .pst file, choose Start, then Repair. Let it make a backup when it offers.
Restart Outlook.

For Microsoft 365, Outlook.com and Exchange accounts the mail lives on the server and Outlook keeps an .ost copy. If that copy is damaged, Microsoft's advice is to let Outlook rebuild it: close Outlook, rename or delete the .ost file, and reopen Outlook so it downloads your mail again. Back up first if you keep any local-only folders.

Step 6: Disable Problematic Add-ins

Third-party add-ins sometimes interfere with Outlook operations.

Open Outlook in Safe Mode: press Windows + R, type outlook.exe /safe and press Enter (or hold Ctrl while you open Outlook).
If mail works in Safe Mode, go to File > Options > Add-ins, choose COM Add-ins > Go, and untick add-ins one at a time.
Restart Outlook normally and test functionality.

Step 7: Create a New Outlook Profile

If the issue persists, create a new Outlook profile: open Control Panel, select Mail (Microsoft Outlook) > Show Profiles > Add, set up the email account in the new profile, and choose Always use this profile for it. Keep the old profile until you are sure nothing is missing.

When to Contact IT Support

If Outlook continues to experience issues after completing the above steps, professional assistance may be required. Problems involving Exchange Server, Microsoft 365 synchronization, or mailbox corruption often require advanced troubleshooting.

Most Outlook sending and receiving problems can be resolved by checking connectivity, account settings, mailbox storage, and Outlook data files. Following these steps can restore normal email operations and minimize business disruption.

Frequently Asked Questions (FAQ)

Why are my emails stuck in the Outbox?

Usually Outlook is in Work Offline mode, the message has a very large attachment, or your password needs updating. Turn off Work Offline on the Send / Receive tab and move large messages to Drafts.

How do I start Outlook in Safe Mode?

Press Windows + R, type outlook.exe /safe and press Enter. This starts classic Outlook without add-ins.

Where is SCANPST.EXE?

In your Office installation folder, for Microsoft 365 usually C:\Program Files\Microsoft Office\root\Office16.

Does this work for the new Outlook for Windows?

Partly. The new Outlook has no PST repair, profiles or Safe Mode. Check your connection, sign-in and mailbox space, and test the same account in Outlook on the web.