Outlook is always “Synchronising folders” (according to the status in the bottom right-hand corner of the Outlook window) which prevents Outlook from completing other activities such as sending email. Having Googled this problem it is clear that many other users experience the same issue, but there does not appear to be a clear solution. The computer is running Windows XP Home Edition.

You are quite correct that many users experience the synchronising folders problem in Outlook and this appears to be a problem which does not have a definite resolution. Therefore, to determine the cause of the problem will involve more of a process of elimination and hopefully achieve a resolution. First, one of the more common causes of the problem seems to be the firewall installed on your computer. It is possible that the firewall is blocking Outlook from completing an operation that is involved in the “synchronising folders” process, thus causing Outlook to hang when attempting to complete the process. If you are running a third-party firewall on your computer make sure that the Windows Firewall has been disabled, to avoid any potential conflicts between the two firewalls. To check whether the Windows Firewall is disabled, go to the “Start” menu > “Control Panel” and open the “Windows Firewall” control panel (you may need to first click the “Network and Internet Connections” category). Make sure that the Windows Firewall has been set to “Off” as your third-party firewall should be providing sufficient protection against any internet-based threats. Assuming that the Windows Firewall is disabled, and the problem persists, you should check the settings for your third-party firewall. In fact, it may be worthwhile disabling the firewall momentarily to check whether the problem ceases or continues. However, before doing this be aware that once you disable the firewall you are leaving your computer open to attack, so make sure you understand the security implications and also that your computer has the latest updates from Windows Update to patch any known security vulnerabilities before attempting this relatively risky procedure. However, should disabling the firewall cause the problem to stop, then, after immediately re-enabling the firewall to provide protection for your computer, you should check the settings within your firewall as it seems that something within the firewall is causing the problem.

Should disabling the firewall not resolve the issue, the next possibility is to create a new Outlook profile in case the problem is related to your profile. Even though this is a fairly cumbersome process, as you will need to transfer all the email contained in your current Outlook profile across to your new profile, it is a worthwhile troubleshooting step. The first step in the process will be noting down all the settings for your email account so these can be recreated in the new Outlook profile. In Outlook, go to the “Tools” menu > “Account Settings”. In the Account Settings window that appears, click the “Email” tab then select your email account and click the “Change” button. Write down all the email account settings contained within the window. Once this has been done click “Cancel” to return to the main Account Settings window. Next, we need to locate the PST file which is storing all your Outlook information (e.g. email, calendar, etc). It is important that we locate this file so when the new Outlook profile is created we can import all your Outlook data into the new profile. In the Account Settings window, click the “Data Files” tab. You should see one entry on this tab with the name “Personal Folders”. You may need to expand the “Filename” column to see the entire path and name of the PST file. Write the filename and location down. Then, open My Computer and navigate to that path. You may need to enable the display of hidden files and folders by pressing the ALT key on the keyboard and then “Tools” menu > “Folder Options” > “View” tab then enable “Show hidden files and folders” and click OK. Once you have located the PST file, make a copy of the file. Right-click on the file and select “Copy” and then right-click in any empty space within the folder and select “Paste”. The file should be copied with a name like “Copy of Outlook.pst”. We have made a copy of the file so that when we do the import we are never operating on your real, live version (just in case something goes wrong). Once you have copied the PST file we will create a new email account in Outlook. Select the “E-mail” tab and then click the “New” button. Setup a new email account using the same settings as your old email account.

Having setup the new email account that should now appear in your list of email accounts. However, email will still be delivered into the same Outlook PST file as the old email account, so we need to change the PST file used for storage. Highlight the new email account and click the “Change Folder” button. In the New E-mail Delivery Location window that appears, click the “New Outlook Data File” button. Select “Office Outlook Personal Folders (.pst) File” and click OK. Name the PST file “Outlook_New.pst” and click OK. Leave the properties (e.g. name, password) at their default values and click OK. The new delivery location should be automatically selected in the New E-mail Delivery Location window, so click OK to save and close. You should now be back in the main Account Settings window. With the new email account still highlighted, click the “Set as Default” button. We also need to set the new PST file as the default mail store location. Click the “Data Files” tab and select the new Outlook PST file and click the “Set as Default” button. Click “Close” and then restart Outlook.

Finally, we need to import the data from your old PST file into the new PST file. To do this, we will import your “Copy of Outlook.pst” file into your new Personal Folders folder structure. You may have noticed that at the moment you have two Personal Folders structures in Outlook – one representing your new Personal Folders PST file (Outlook_New.pst) and another representing the old Personal Folders PST file (Outlook.pst). An easy way to determine which is the new and which is the old is the new Personal Folders structure will not contain any items and the old Personal Folders structure will contain all your email. Before going any further we need to close the old Personal Folders structure (and, in the process, close the Outlook.PST file) otherwise this may interfere with the importing of your data into your new Personal Folders PST file. In the main Outlook window, within the left-hand pane right-click on the old Personal Folders structure (i.e. the one which contains all your email) and select “Close Personal Folders”. This should disappear from the left-hand pane.

Once you have closed the old Personal Folders PST file, we are ready to import all your data into your new Personal Folders PST file. Go to the “File” menu > “Import and Export”. In the Import and Export Wizard window that appears, select “Import from another program or file” and click “Next”. In the next window select “Personal Folder File (.pst)” then click “Next”. You will now need to select the file you wish to import. Click the “Browse” button and navigate to the location of the backed-up PST file. Then, select the “Copy of Outlook.pst” file and click “Open”. For the options select “Replace duplicates with items imported” (this should not really matter, as the new PST file is empty) and click “Next”. For the “Select the folder to import from” select the root “Personal Folders” entry and make sure that “Include subfolders” is ticked. As the import destination, select “Import items into the same folder in” and choose “Personal Folders” (you should only have one option) then click “Finish”. Your data should be imported into the new Personal Folders structure. At this point, restart Outlook and then check whether the problem persists.

However, should the process of creating a new Outlook profile and importing your data still not resolve the problem we should next look at the contents of your Inbox in Outlook. Some users have reported that the synchronisation problems occur when there is a large quantity of unread mail in their Inbox. As a first step, try ensuring that all messages within your Inbox have been marked as read. Should you need to do this en-mass, highlight all the messages in your Inbox by using CTRL-A (or the “Edit” menu > “Select All”) then right-click on the selection and click “Mark as Read”. Once this has been completed, check whether the problem continues. If so, another alternative is create a new Outlook folder (e.g. named Inbox Temp) and then move all the messages from your Inbox to this new folder, leaving your Inbox empty. Restart Outlook and check whether the problem has been solved. If so, this doesn’t give us a good reason as to why the problem occurs but it does give you a workaround (moving messages to a different folder, rather than leaving them in the Inbox).

As a final suggestion, somewhat related to the above point, if you have a large number of email messages in some of your folders then you may wish to consider moving these into the Outlook Archive, as it is possible that Outlook is trying to do something with the messages and, given the number and combined size of the messages, is failing. The best example might be if you have a lot of items in your Sent Items, which you should archive. Alternatively, you may have a lot of items in the Deleted Items which you should empty. If you need to archive a folder you can find the Outlook Archive function on the “File” menu > “Archive”. Follow the steps to archive particular folders within Outlook. Please let me know how this goes and whether you were able to attain a resolution to the Outlook issue.