My Outlook is really slow with Hotmail accounts but fine on anything POP3.
It doesn't seem to keep a record of what's been synched already i.e.: if I do a send/recieve on a Hotmail Inbox it synchs the whole box - taking 20 minutes or so - but next time I load Outlook up they're all not synched again.
When I move to a Hotmail Inbox, it can be 30-60 seconds saying "synchronizing message headers" or times out with an error.
Is there a simple fix?
Actually there is, as it sounds like you are using Outlook’s default HTTP connection to connect to your Live Hotmail account.
Update: Connecting to Hotmail over HTTP has been discontinued completely as of September 1st, 2010. Trying to configure a Hotmail or Outlook.com account in Outlook 2003 or Outlook 2007 via the HTTP protocol will result in the error:
Task 'Hotmail: Folder:Inbox Synchronizing headers.' reported error
(0x800CCC33) : 'Access to the account was denied. Verify that your username
and password are correct.The server responded 'Forbidden'.
Outlook Hotmail Connector
A long technical story short; the way of connecting to Live Hotmail accounts has been replaced by using a special add-in which is optimized for the new features and larger mailbox sizes of Live Hotmail and has a far better caching mechanism than the default HTTP connection.
This special add-in is called the Outlook Hotmail Connector and can be installed via the Windows Live Essentials suite or downloaded individually via the links below;
Note 1: You will only need to install the 64-bit version when you are using the 64-bit version of Outlook 2010.
Note 2: If you prefer to download your Hotmail/Outlook.com messages via POP3 or IMAP instead of using the Outlook Hotmail Connector, you can find the settings needed in this guide.
Note 3: The Outlook Hotmail Connector doesn’t work with Outlook 2013. To configure an Outlook.com/Hotmail account, use the Exchange ActiveSync (EAS) account type.