I was about to move from Eudora to Mail 4.3 until. . . I read MacUsers review of MailSteward (UK EDition 16th July 2010), which starts, "The more accumulated burden of years of emails hinders Mail's performance, the more attractive archiving becomes." MailSteward is seen as a solution to archiving. As a Eudora user, I don't understand how and why Mail becomes overburdened with the accumulation of years of emails. If old emails are transfered to other Mail mailboxes, doesn't Mail ignore them if they are unopened and unused? In Eudora, I archive old emails by clearing out a year's worth at a time into new mailboxes with names such as "2007in" and "2007out". If I close mailboxes, it seems that Eudora doesn't load them until I use them again. At any one time very few mailboxes are open or loaded and Eudora doesn't seem overburdened although I have emails going back to 1996, if I care to view them. I don't have to archive such old emails in MailSteward or anything similar, the old mailboxes are always available to be opened or searched in Eudora, with no detectable performance hit.