What is the maximum number of proxyaddresses for a Distribution Group object in order to sync?

In a hybrid environment (dirsync ad objects), I currently have a Distribution group with 800+ proxyaddresses (mostly RFAX:xxxx@).

This object is unable to sync.  Error messages states:

The provisioned object is too large. Trim the number of attribute values on this object. The operation will be retried in the next synchronization cycle.

What is the maximum number of proxyaddresses for a Distribution Group in order to sync?

I am already aware that RFAX proxyaddresses do not replicate to the cloud.  But I still need that object synced to the cloud because of valid smtp address.

Thanks.