Email archives tend be voluminous. While, storage space costs money moving large amounts of critical data can be very expensive in terms of time and integrity, so planning beforehand and using the right tools is vital to a successful migration. The article referenced in the link below gives you an overview of the most important elements that should be present in an email archive migration strategy.
The article by Stephen Bird, marketing executive at TransVault recommends to:
- Be selective in what you take (but be realistic)
- Don’t forget the end-user experience
- Check for breakages before you move
Read the full article here - http://www.transvault.com/news-item.php?id=62