This issue has been mitigated and we are continuing to monitor the issue to ensure stability. The root cause was the deployment of an incorrect campaign data file, which led to false positive campaign detection. We have since reverted to the right data file and the outbound email flow has returned to a normal state.

For newer versions (2010 and later), check the Send/Receive Groups and disable scheduled sending/receiving. If you don’t want to go with the manual methods to fix these errors, you can directly go with the Outlook PST Recovery Tool. It is highly recommendable or suggestive by IT Professionals and experts.

We can fix the problem for you, or you can use the troubleshooting steps we're providing below to help resolve these startup issues. Outlook stores all your email messages, meetings and events, contacts, and tasks in data files. You can run the Inbox Repair Tool (scanpst.exe) to scan your Outlook data files and repair errors. The only thing is to know how to overcome them when they arise. Whether it's defective add-ins, frozen Outlook, faulty data files, and many others, you can manage all these problems yourself. Knowing the cause of the problem will help you sort out all the issues related to Outlook opening.

Try to open Outlook in Safe Mode and Disable Add-insPress the Windows button and R keys together.Type Outlook /safe in the Run window and select OK.The Choose Profile dialog box is displayed. Accept the default Outlook settings and choose OK.If prompted, enter the password, and then click OK.

If you can't choose any of the menu options, type inside an email message, calendar event, or contact, Outlook may have frozen. There are three steps you can take to try to get Outlook working again. However, if you encountered other issues like Outlook not responding, learn how to fix Outlook not responding here. Click the above link to have a quick download, then you can have Outlook errors fixed within minutes. Check the solutions to fix "Outlook not opening" problem and how to avoid "Outlook won't open" again. Here are some common fixes that should work when Outlook doesn't open, whether you're using Windows or a Mac.

Be aware that if you are connecting to an Exchange Server mailbox, your mailbox or your email messages are already being scanned by antivirus software on the server. For more information, see You may experience application pauses if you have a large Outlook data file. Optionally, if you have a Microsoft Exchange online archive, you can move items to that archive or create retention policies to automatically dispose of older items.

In System Configuration, if you select a check box, the related service or startup program runs when you restart the computer. If the check box is cleared, the service or startup program doesn't run when you restart the computer. When you start Windows normally, several applications and services start automatically and then run how to repair Outlook quickly in the background. A Selective Startup or "clean boot" process can help you identify problems that are caused by application conflicts. To keep up with new viruses as they're created, antivirus software vendors periodically provide updates that you can download from the Internet.

To get support in Outlook.com, click here or select Help on the menu bar and enter your query. If the self-help doesn't solve your problem, scroll down to Still need help? Visit Firefox support to learn how to Disable or remove Add-ons. Some users may not be able to empty their Deleted Items folder.

Starting Outlook in safe mode, which starts Outlook without add-ins loaded, can tell you if an add-in is the source of the problem. Turn off all the add-ins, close Outlook, and reopen it (not in Safe Mode). If it opens correctly, you can enable the add-ins one by one. After turning on each one, close and reopen Outlook to see if it loads correctly. It will help pinpoint the troublesome add-in you can remove or replace.

You can automatically repair your Office program files to resolve such problems as Outlook freezing or not responding. To manage your mailbox by reducing the size of the Outlook data file, see Reduce the size of Outlook Data Files (.pst and .ost). Many of these items can be automatically checked by the Classic Outlook Advanced Diagnostics troubleshooter.

Avoid using unstable or low internet connection and use a reliable and high-speed internet connection with reasonable download/upload speed. You must have encountered Outlook Connection Error occasionally. The reason behind this error is an invalid entry of the target how to repair Outlook quickly machine, problems with DNS resolution or an incorrect IP address. Resolve this error by verifying the server’s name or checking the DNS resolution. Some common Outlook errors are listed below with the solutions to fix them. Let’s find out the reasons that caused this error and acquire a knowledge of how you can tackle these errors.

For a list of antivirus software vendors, see Consumer antivirus software how to repair Outlook quickly providers for Windows. If the problem doesn't occur after you restart Outlook, one of the add-ins is likely the cause of the problem. Restore the add-ins one at a time until the problem does occur to determine which add-in is causing the problem. Although add-ins can enhance your user experience, they can occasionally interfere or conflict with Outlook. Upgrade to Microsoft Edge to take advantage of the latest features, security updates, and technical support.