>Please notice that allowedDomains is set in config_template.xml
you must *deploy* the zimlet for this to work. But, if you have your zimlet in _dev folder as well, it would create two zimlet instances. So, one way to do this is to create a dummy zimlet and set alloweddomains in that, then deploy that dummy zimlet. After that your actual zimlet in _dev will start working.
other way is to set it through backend.. zmprov mc <COS> +zimbraProxyAllowedDomains <externalAPIserver> |