[Dovecot] Email client dowloads previously read messages as new during migration.

[Eric and Barbara Sammons]

I am migrating from UW to dovecot and using mbox.  I have been able to find
mbox to maildir migration information and tools; however, I have had little
luck finding any tool or information for performing such a migration where I
wish to keep mbox.  ( I know I should migrate to MailDir, but in the case I
wish to take baby steps.)

I have setup dovecot pop3 communication and I go to my email client and
everything works fine with the exception that all mail I have previously
read (when using UW as my POP server) is downloaded again as NEW.  Is there
a way to prevent this from happening without setting my client to delete
mail from server?

thank you!