slow with google apps

I’m trying eM client with Google Apps because I want to find an alternative to MS Outlook with Google Apps Synch tool. 
First, I like very much your product and the way it “interacts” with Google. The only problem is that sometimes I click on a folder and it takes a while before showing its content (30 seconds, more or less).
At the moment I’m downloading headers only. I know I could have a better experience if I download email for offline usage…but I’m really scared about it, because we all have something like 5-8GB inbox here at my company.
Do you have an option similar to Google Apps Synch, that allows me to have only the LAST 1GB or 4GB for offline usage?
That would be great. It would be the option that make me switch from MS Outlook to eM Client (me and all here at my company).

Thank you for your help.

Hi Filippo, unfortunately it is not currently possible to limit the bandwidth or the maximum database size for eM Client to allow you synchronize only the most recent items for offline use, however we’re considering to improve this in future releases of eM Client.