First, it may be that you have a message coming in that is too large or corrupted. If you only have one email account coming in through Outlook Express, call your email service provider and tell them to clear your email incoming messages. You will lose all of the ones that have not been downloaded yet, but that will end the freezing and the messages in your Outlook Express folders will still be there.
If you have more than one email account coming in through OE, you need to find out which account is causing the jam.
Disconnect the computer from the internet.
Restart the computer.
Open Outlook Express.
When it tries to download email, click Tools, Send and Receive All, Stop and close that window.
Click Tools, Options, General tab.
Uncheck the box: "Send and receive messages at startup."
Click OK as many times as necessary to close all screens except the main OE screen.
Reconnect the computer to the internet.
Click Tools, Send and Receive, and click on the first account. If it downloads messages and OE doesn't freeze, that account is not the rascal. Click Tools, Send and Receive, and click the next account. If the computer freezes, call customer support on that account and get the incoming messages deleted.
If that does not end the freezing problem, temporarily delete that account and see if that solves the problem. Here's how: Click Tools, Accounts. Select the account. Click Properties. Use pen and paper to make notes of all of the settings in all of tabs. That way you can reinstall this account later. Then click OK and click the Remove button. Then OK (or Remove, I don't remember which).
Restart the computer and see if the problem is solved. If that solved the problem, reinstall that account into OE. Click Tools, Accounts, Add, Mail, then fill out each screen using your notes.
If deleting that account didn’t solve the problem, call customer service. It is now their problem.
If deleting accounts doesn’t solve the problem, or if the freezing occurs on every account, Outlook Express may have a software corruption. First save all email that you want to save, then uninstall Outlook Express and then download a new copy from Windows Update, and reinstall it.
Saving all email from the Inbox and Saved Items folders might take a long time, but you should have been doing this every week or every month and there is no choice now.