No specific info about version 6.1. Please visit the main page of Postbox on Mac Informer.
Manage your Gmail account directly from your desktop.
This AppleScript converts all emails in the Address Book to lowercase.
Account Switcher app will automate switching between user accounts on the Mac.
With Beyond Inbox you can backup, transfer and restore your mailbox.
Inbox Archiver allows you to archive all online accounts to your Mac.