SysTools EML to PST Converter - Allow to convert multiple eml files into single PST file, which is importable in MS Outlook.

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.

EML to PST Converter - EML to PST Converter is an ultimate email conversion and migration tool.

imapsync - Console-based utility for migrating IMAP mailboxes.

ReliefJet Essentials for Outlook - A large set of useful and easy-to-use tools for every Microsoft Outlook user: Import, export and convert using EML,MSG,TXT and PST formats; remove duplicate items, process attachments and extract addresses; get reports and statistics and even more...

Gmvault - Backup the emails in your Gmail account.