imapsync - Console-based utility for migrating IMAP mailboxes.

MailStore - MailStore Home - A 100% free single-private-user desktop solution

Cryoserver - Cryoserver is an all-in-one email archiving solution that empowers you to preserve your email in a tamper-evident archive, making you transform your data into a useful archive for everyday use.

audriga Email and Groupware migration - Easily migrate your email, contacts, calendar items and tasks to your new provider or server. No software installation is required.

MailMeter - MailMeter is a software that allows cloud or on-premise-based email management and compliance platforms, helping you to locate every single email in your organization, conduct eDiscovery, freedom of information, and DSAR’s searches from your emulato…

isync (mbsync) - mbsync is a command line application which synchronizes mailboxes.