Sometime user may get error that "Outlook Not Responding". Here we are briefing common reasons and solutions of this error.

Common Reasons

There are can be many reasons due to which Microsoft Outlook stops responding. Some of the common reasons causing Outlook to stop responding are as follows:

• Outlook.exe Is Suddenly Resource-Hungry : Microsoft Outlook is probably the most complex email application for Windows Operating System. This is because of the reason that Outlook offers too many features and also it is designed as a connectivity tool with other software and hardware products. As a result, its stability also relays on third-party tools. In case of a badly designed part of any software, Outlook can start to require more and more system resources, which can cause it to crash and even to stop responding totally.
• Auto-archiving or Synchronization in Progress : By default, Outlook is configured to archive Inbox emails automatically, which helps in decreasing the size of Outlook mailbox files. Also, when a communication device (such as a PDA or a mobile phone) is connected to your computer, in most cases, Outlook will attempt to connect to it. Outlook can connect to it via ActiveSync or 3rd party sync tools in order to synchronize the mailbox messages and contacts with the mobile device. During the archiving or synchronization processes, Outlook starts needing more and more system resources and its response times also becomes very high. If you keep performing such actions, sooner or later Outlook will stop responding.
• Using IMAP or Exchange Accounts : If you are using an IMAP or Microsoft Exchange email account, Outlook offers you some special features like downloading of partial emails (email headers only) and the offline mode in Outlook. If any of your Outlook session is not connected (online) on the Exchange server or if you configured Outlook to download/receive only email headers, you must be aware that it will take more time for Outlook to browse and display your Inbox messages. That happens because Outlook needs to connect to your mail server and retrieve the rest of the message, so you can preview it. This can cause Outlook to stop responding.
• Oversized Outlook Mailbox Files : The more emails you receive and store, the greater the Outlook mailbox file size. As the mailbox file size starts increasing gradually with time, Outlook starts taking more and more time to open each mailbox folder. Now, if you try to browse many folders at a very fast speed, while Outlook is still struggling to display their contents, you are likely to encounter the error message stating, "Outlook not responding.
• While Starting – Outlook Not Responding : When Outlook starts, it needs to locate and load your mailbox file and your Outlook profile add-ins (if any). Sometimes, Outlook stops responding as you try to open it.
• Anti-spam and Anti-virus Programs : Apparently, all anti-spam and anti-virus programs are designed to keep you secure and away from junk or Malware emails. However, an excessively secure anti-spam/virus program, with too tight security settings, can in-turn cause improper functioning of Outlook or Outlook add-ins. For example, if you are using an email auto responder program, Outlook must send automatic emails. This functionality can conflict with some anti-virus programs that incorrectly handle the automated messaging system. As a result, the anti-virus program will block the add-ins and consequently, Outlook stops responding.