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.
MailsDaddy OST to PST Converter - Download MailsDaddy OST to PST Converter software to retrieve Offline OST file data and export in PST and many various format like-EML, MSG, HTML, RTF, MHTML, MBOX, Office 365 and Live Exchange Server.
imapsync - Console-based utility for migrating IMAP mailboxes.
ZOOK EML to PST Converter - Batch Convert EML to PST format to Migrate Windows Live Mail to Outlook PST
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.