Oxford Journals provides the configuration needed for EZproxy at http://www.oxfordjournals.org/help/techinfo/ezproxyconfig.txt which includes current entries for all of the oxfordjournals.org hostnames as well as compatibility entries for the older oupjournals.org hostnames. This file is maintained by Oxford Journals.
When you are creating starting point URLs to use as links on your library webpages, please ensure that the URLs you are using as target URLs are included in this database stanza. If you do not see the target URL you are using, you will need to add it manually as a Host or HJ statament to the Oxford Journals stanza in your config.txt. For more information on this topic, please see Starting Point URLs and Starting Point URLs and config.txt.