Lastly, be sure to empty the Trash folder frequently enough to avoid a constantly growing Trash folder. Also, you can simply archive messages in outlook to clean them out of your mailbox (be careful as this WILL remove the messages from the server). The recommended method of avoiding this outlook issue is to simply file away messages from these subscribed folders into archived / unsubscribed folders (this also keeps you email organized!). This issue can still be noticed if you have a very large Inbox folder, Sent folder, Trash folder, or any subscribed folder. When you are prompted for your 'Display name', enter your full name, and click Next. To start the Internet Connection Wizard, select Mail. This will resolve extremely slow synchronizations with Microsoft Outlook platforms. From the Tools menu, select Accounts., and then click the Add button.

Click “OK” to close the window and commit the options.

Uncheck the option “When displaying hierarchy in Outlook, show only subscribed folders.” at the bottom of the window.

Do this for any other folders you wish to sync with the server.

Select “Templates” and click subscribe.

Select the “All”tab as we are now going to sync folders we wish or need to sync.

It may prompt about folders that cannot be unsubscribed, just click “OK” here.

Create IMAP Account Deleted Items Folders Manually. You can now create sub-folders in this folder. Navigate to your Outlook IMAP Account and Select your Inbox Right-click on Inbox Folder and Select IMAP Folders option In IMAP Folders dialog box, Click Query > Select Deleted Items > Click Subscribe To confirm that you have successfully subscribed to the Deleted Items folder, check the folders on the Subscribed tab. Click on 'Query', and scoll down the list to the new folder you just created, and subscribe to it.

Hold shift and click the last item in the list. Then, in your email client (Outlook XP in this examle), right click on the root folder for the account, and click 'IMAP Folders.'.

Select the first item in the list and scroll all the way down.

Select all items in the list as follow:.

Click on the “Subscribed” tab and click the “Query” button.

After setting up your IMAP email account in outlook, right click on your email account and select “IMAP Folders…”.

This issue is because Microsoft Outlook downloads all messages every time including attachments versus a normal email IMAP application where only headers are synced to present crucial information only, and messages and attachments are ONLY downloaded and cached upon viewing the message or if the mail application is explicitly told to download all messages. Having many folders with many messages in Microsoft Outlook, especially if they have attachments, can be slow.

Outlook express 6 subscribe to imap folders