Having access to the important documents that you have stored in your email account, even when you don't have an Internet connection, can be a great advantage. Applications like Zimbra Desktop make it possible for you to check your emails offline by synchronizing all data within any of your email accounts.
A great thing about using this program is that you can manage multiple email accounts from a single user interface. To me, this feature comes as a relevant advantage since I'm using three different email accounts on a daily basis. The first thing you need to consider before using this program is to have an Internet connection so that the program can sync the data from your email accounts and make it accessible offline. Just enter the details for all of your email accounts and let the application get the job done.
If you want, you can test if it works without an Internet connection by clicking the Offline button. You can then check for old emails from your co-workers, look into your calendar and scheduled tasks, search a contact in your address book and many other.
The only issue I have with this application is that it takes a long time to update the email accounts, no matter how fast is your Internet connection.
Briefly, despite its only flaw, I still consider Zimbra Desktop to be an efficient solution when it comes to working offline with my email account. And the fact that you don't have to pay to use it is just another good reason for you to give it a try.