Typically I always associated
Microsoft Transporter with Lotus Notes migrations to Exchange.
Coworker Britt Baubie pointed out that Microsoft updated the suite a few days ago and they now support migrating non-Lotus POP3 and IMAP servers to Exchange 2007.
As seen in the release notes
here, here are the details:
Transporter Suite for Internet Mailboxes
A whole new console and tools for migrating POP/IMAP Mailboxes
Migration of mailbox content from generic servers through POP or IMAP to Exchange 2007.
Preserves all messages and
folder structures.
Preserves rich content including formatting, message flags and
even calendaring through iCAL.
Exposed through GUI and a rich set of PowerShell tasks
It looks like migrating to Exchange 2007 just got easier for a lot of software packages.