combining results from multiple database servers

If I have a table called "customers" that is distributed across
several database servers, is there a way I can build a model that will
query all of the databases and return a combined result ? For example,
I'd like to query for all customers using a gmail email account, but
the data is partitioned by customer last name, so this must be
combined from multiple servers. The same schema exists on all servers.
Thanks for any help.