imapsync - Console-based utility for migrating IMAP mailboxes.
ZaapIT - Mass Merge, auto merge, duplicates cleanup, bulk edit, bulk update, bulk delete , mass lead convert
Gmvault - Backup the emails in your Gmail account.
Duplicate Check - Start creating data happiness. Find, merge and prevent duplicate records in your Salesforce Organization.
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.
Apsona for Salesforce - Apsona for Salesforce is an add-on application for Salesforce to manage the data.