Moved to SaaS for better attention.
The following are the datacenters North America, Europe,Asia, and Australia; also you have asked how it travels and is there any diagram representation for the message which is getting Archived.
Since it is a cloud based service there is no clear structure like how it travels/diagram representation.
The data centres are set up in pairs. In our region, we have a DC/PoD in Sydney (Australia) and another in Auckland (New Zealand). They are configured in an active-active state so email may be collected within the interface (which triggers local IMAP/POP collectors) from either PoD, and then replicated to the other. The end result is that the data is stored in both locations, and during an outage the ops team adjust the routing of inbound traffic to access the PoD that is available. I believe it works the same in each region. Configured correctly, data is secured both in transit and at rest.
Hope this helps.
--Andrew Johnson, Manage Protect.