MailStore - MailStore Home - A 100% free single-private-user desktop solution
Apsona for Salesforce - Apsona for Salesforce is an add-on application for Salesforce to manage the data.
Gmvault - Backup the emails in your Gmail account.
Regain Office 365 to PST - Export or migrate Office 365 Mailbox to PST, EML, EMLX, MBOX, MSG and vCard format.
Mail Backup X - Your one stop mail backup and archiving tool for Mac.
SysTools Office 365 Backup - Instantly backup your Office 365 Mailbox to PST / EML format with SysTools Office 365 Backup & Restore software for MAC and Win.