Messaging supports full E.164 mailbox numbers in the system. Administrators can configure mailbox numbers without using the full E.164 number and map these mailbox numbers to a full E.164 number. Therefore, users at any site can continue to use mailbox numbers locally that are smaller in length but are still uniquely identifiable in the local context.
Messaging supports only the fixed mailbox number length system wide. Messaging does not support variable length mailbox numbers.
Messaging provides the ability to centralize the Messaging system using full E.164 mailbox numbers. Yet, each site has the ability to have shortcut mailbox numbers.