Best way to track changes?

[MacTI]

I have a need where I have to track changes to events and contacts and a change occurs, to send a notification to an external application. For example, User A deletes a contact from his iPhone, Zimbra Mobile is notified of the change, and after the contact must be deleted to an another application (via a Web service or other way).

Does the only way to achieve this is to modify ZCS source? Can we modify the source even if it's a Network Edition installation?

[dkarp]

You could use the SyncRequest SOAP call to track changes via polling. You could also write an extension that registers listeners on the Mailbox objects. Neither requires altering Zimbra code.

[MacTI]

Ok, I just found out about SyncRequest, and I think it will do the job. Thanks for the listeners tip, I will look at it if SyncRequest don't cover my needs.