If you have a large number of items in any single folder, you may experience performance issues during certain operations. For more information, see Outlook performance issues when there are too many items or folders in a cached mode .ost or .pst file. When you install Office, an Inbox Repair Tool (SCANSPST.EXE) is also installed on your PC. The Inbox Repair Tool can resolve issues by scanning your Outlook data files and repairing errors. If your antivirus software includes integration with Outlook, you may experience performance issues.
First, let’s look at the most common reasons the Outlook app is so slow to open and how Clean Email can remedy each one. We’ll then delve into more technical and application-specific causes with recommended solutions. When you have to deal with a slow or unresponsive Outlook, it can be frustrating. Troubleshooting Outlook Startup Issues Whether on Windows, Mac, or mobile, a laggy email client can hinder productivity and disrupt communication. This guide explores why Outlook is so slow to respond across platforms and how Clean Email can help improve inbox management and speed up Outlook. Corruption or inconsistencies in the Outlook data file (PST) can cause Outlook to run slow.
To learn more about how to share your feedback, see How do I give feedback on Microsoft Office. Customers using the contact support buttons at the foot of the support pages, or the "email us" links in support Virtual Agent, are unable to open the Help Pane. If you access your Outlook.com account through the iOS Mail app, you may be repeatedly asked to enter your username Troubleshooting Outlook Startup Issues and password.
A damaged or corrupted Outlook user profile is a common reason for "Outlook won’t open" errors. Creating a fresh profile can provide a clean slate for Outlook to start. 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. Are you having trouble starting Outlook or receiving Troubleshooting Outlook Startup Issues "Cannot start Microsoft Outlook. Cannot open the Outlook window" error messages?
When you have a weak or unstable internet connection, it can cause the app to load slowly, especially on mobile devices. If you’re using an outdated version of Outlook, it can result in slower performance due to a lack of necessary updates and improvements. If a specific version significantly impacts performance, such as CPU you could navigate to the "High CPU usage" diagnostics dashboard and look for the Outlook binary. Some of these data-gathering remote actions are used to populate the live dashboard and should already be scheduled. You can query the results by investigating KPIs from the Live dashboard or from your own investigations. Restart Outlook and check the performance of the Outlook application.
However, you can repair the Outlook data file (PST) using ScanPST.exe, also known as the Inbox Repair Tool. You can follow the below solutions to troubleshoot and resolve the Outlook running slow issue. This guide highlights the causes behind these issues and lists troubleshooting methods to resolve the "Outlook is running slow on Windows system" issue. If you are using an Exchange account in Cached mode, compacting your OST file may help improve performance.
To sum up, we explored several methods to fix "Outlook won’t open" errors. Whether it’s a profile issue, a corrupted PST file, or faulty add-ins, the methods above can help you get Outlook running again. When Microsoft Outlook refuses to open, it’s incredibly frustrating. This issue often stems from common culprits like a corrupted user profile, a damaged data file (PST or OST), or even a minor conflict within its settings or add-ins.
So, we have produced this list of general things to try to resolve your problem in Outlook. To edit a shared calendar, go online to your own Outlook.com calendar, open Calendar for Windows 10, or use a mobile device. If you're still unable to send or receive email, read how to Fix Outlook.com email sync issues. Blocking someone doesn't stop their email from coming to your mailbox, but it does automatically move the message to your Junk Email folder where you can review it (in case it was blocked in error).
Outlook.com (the web version of Outlook) and Outlook apps require a 1st party alias (Outlook/Hotmail/Live/MSN) to send and receive email, use calendar, etc. Occasionally, classic Outlook tries to run a process in the background. Auto-archive, sending and receiving a very large attachment, or running some of the other mailbox tools Troubleshooting Outlook Startup Issues can all be done in the background. Check the status bar at the bottom of the screen to see if another process is running. If so, wait a short time (usually two or three minutes) to see if Outlook starts working again.
Give Outlook a few minutes to finish the process and it should start to Troubleshooting Outlook Startup Issues work again. If Outlook isn't stuck at a screen that says "Processing," or this didn't resolve your issue, continue to the steps below. If those steps don't work, see Need additional help?