If you've successfully connected your Exchange account to Robin, changes should sync back and forth between the two systems in a matter of seconds. In some cases, you may discover an issue like this:
- Changes made in Robin successfully sync to Exchange
- Change made in Exchange do not sync to Robin
This typically means you have a firewall, proxy, or other configuration which blocks your Exchange server from updating Robin as changes come in.
What's stopping the sync?
During the initial calendar set up, Robin subscribes to a new push notification channel for that resource on your Exchange server. This allows your Exchange server to notify Robin whenever a change on the calendar is made, leading to faster updates and less strain on your service.
On the other hand when changes happen in Robin, we notify your Exchange server of the change and update our copy with the results. This is why you may find Robin-created events syncing properly even though the other way is silent.
How to fix outgoing Exchange notifications
First make sure you've whitelisted Robin's service IP addresses.
Double check that your firewall allows outgoing connections for Exchange. If you use a proxy, make sure the Exchange server is allow to use that for outgoing traffic as well.
You can find guides for this on MSDN: Push Event Notifications and Proxy Servers.
FYI: If you use a proxy, you may need to apply the configuration to EWS's web.config so it can successfully send outgoing push notifications to our syncing service. Keep in mind that this file is parsed in order, and in most cases the configuration should be at the bottom of the file.