exchange/pst import wizards slow in multi-node setup with slow inter-server connectio

[Hivos]

Hi,

We run a multi-node Zimbra 6.0.6_GA_2330.UBUNTU8_64 that consists of 1 master at our Head Office in The Netherlands and 2 slaves at our Region Office in Bangalore and La Paz. Our servers communication to each-other by means of a VPN (using Tinc). This works fine for a few months now.

But now I am in the process of migrating a Exchange server in our Region Office in Harare Zimbabwe and I have run into a problem while doing the actual migration of all the mailboxes. Both the import wizards (Exchange and PST) work functionally fine but practically they do not. The import process is way to slow and I have figured out that it is due to the poor internet connection here in Harare. Looking at the log-file of the wizards I see that every mail import result in communication with the master server in the Netherlands...

Is there a way around this by temporarily disabling the inter-server communication? And if so, how do I do that?

Regards

Ferry