Sharegate - Sharegate simplifies the migration and management of SharePoint, Office 365, and OneDrive for...
imapsync - Console-based utility for migrating IMAP mailboxes.
AvePoint - AvePoint is the established leader in enabling enterprise collaboration across platforms and...
MailStore - MailStore Home - A 100% free single-private-user desktop solution
SysKit Security Manager - Meet your Office 365 security ally!
Fetchmail - The Fetchmail Project