MailStore - MailStore Home - A 100% free single-private-user desktop solution
MultCloud - Multiple Cloud Storage Manager: Migrate, move, sync, copy, backup and transfer cloud files with MultCloud, which supports Dropbox, Box, Google Drive, Mega, OneDrive and FTP, etc.
Hornetsecurity Email Archiving - Hornetsecurity Email Archiving is one of the advanced software that offers long-term, unchangeable, and secure storage of important company information, data, and flies.
Koofr - Koofr offers safe EU based cloud storage with free storage space for life and options to connect multiple cloud accounts (Dropbox, Google Drive, OneDrive) and your personal storages.
Intradyn Email Archiver - Orca Email Archiver provides email archiving solution for local government and business.
odrive - odrive aggregates all cloud storage. Access, sync, share, and encrypt everything in one place. Integrations to 20+ storage services, desktop sync, Linux support, placeholder files, zero-knowledge-encryption, web client, advanced sharing, and more!