MailCOPA V16.01 is a completely new 64-bit version of this professional email client. There is now no 32-bit version. MailCOPA will also not run on earlier operating systems, Windows XP, Vista or Server 2003
MailCOPA has been updated to use the latest sync APIs from Google. In these new APIs the ID used to track addresses and calendar entries has been changed.
If you have upgraded from an earlier version, MailCOPA will think all the addresses/events you have are new and send them all to Google, which will duplicate all your addresses. Because of this problem, sync will be switched off on any address books and calendars that were synced to avoid duplicating all your data.
It is recommended you create a new book and sync that, then delete your old book. This will cause all your addresses to be copied from Google and have the new ID set correctly. There is also an option to delete local appointments so you can re-synce from Google.
Otherwise, there are only very small changes from the previous version (15.01):overall the functionality is the same.