Beyond Inbox is described as ', backup tool to backup, copy, move and restore email messages of your IMAP account (Gmail backup and Imap backup)'. There are more than 10 alternatives to Beyond Inbox for a variety of platforms, including Windows, Mac, Linux, Online / Web-based and iPhone. The best alternative is MailStore. It's not free, so if you're looking for a free alternative, you could try Gmvault or Got Your Back. Other great apps like Beyond Inbox are Mail Backup X (Freemium), Horcrux (Paid), SysTools Gmail Backup (Paid) and Gmail Backup (Free, Open Source).
Backup and restore your gmail account at will. Liberate your emails and never lose that part of your life. Backup all your emails on disk. Use the full sync mode to backup your entire gmail account in a unique directory.
Your one stop mail backup and archiving tool for Mac. Automatically backup mails from Apple Mail, Outlook for Mac, Office 365 for Mac, Thunderbird, Postbox, Gmail, Yahoo and other mail services supporting IMAP and POP service directly on your Mac.
Horcrux lets you automatically backup your mails from any IMAP supported email accounts with great ease. The best part is, you have an option to restore the backup'ed emails to any other email account, retaining all your tags/folder hierarchy.
Systools Gmail backup is a tool to backup single or multiple Gmail accounts in one go. Software backed up emails into well accepted EML, PST, MBOX and MSG formats. Apart from emails tool saves contacts to vCard and calendars to ICS file formats.
SpinBackup is a cloud backup service, available for Google Apps which protects your data from the most common causes of data loss. It provides daily automatic backups for Gmail, Drive, Picasa and Calendar.