To answer the question, the answer lies in the synchronization between Outlook and Gmail. If you still need to access these emails, simply click on them as usual and it will download the email on the fly, as required. This speeds up the syncronising of these folders. I chose the custom option and enabled the attachments and complete items for my inbox, but then my organised folders which stored all my 'archive' and discussion emails etc, I set to 'Headers' which then only downloads the subject and first few lines of the email and NOT all the attachments etc.
Use the custom behaviour defined below. Download Complete Items including Attachments for Subscribed Folders Download Headers for Subscribed Folders On the page that opens, you'll see the following options:. Go to OPTIONS, Then ADVANCED, Then click the button which says 'SEND & RECIEVE' and highlight the account which is causing you problems. Regarding the original question, I found another solution which may help. So why take the risk and download your emails locally into one file (in the case of Outlook) and pray that it never gets corrupted? The likes of Gmail and Hotmail and Yahoo etc, will always have a better backup system than us users.
First of all, I would ALWAYS recommend IMAP over POP3.
