The text entered exceeds the maximum length

In MSCRM 4.0 you may get the following error when trying to track an email:

The text entered exceeds the maximum length

This is caused because the message ID is too long for the field, has nothing to do with the email itself (message is confusing cause it says text entered, but you not actually entering it). To solve it do the following:

• Open the IE CRM Client.
• Open Settings
• Select Customisation from the left menu and open the E-Mail  entity.
• Open Attributes and Open the messageid attribute
• You should see a text box named Maximum Length with the value 100 in it. Increase this value to 200.
• Click Save and Close
• Click Save and Close
• Click More Actions à Publish All Customisations
• Click Start Menu à Run and type iisreset click Run

Thanks to Oli Ward on the PSS at Microsoft for figuring this one out.