[PERDITION-USERS] Distributed Mailboxes, No User Mapping

Hi All, I appologise in advance if this is a relatively simple question however I haven't been able to find an easy fix. We have several backend servers that contain mailboxes, there is no structure as to which server contains mailboxes (Ie. Alphabetically) nor is there an easy way to suck out a list of which server hosts which mailbox that Perdition can map against. Currently I've configured Perdition to use Regex with a couple lines as follows ^[a-z]: 203.x.x.1 ^[a-z]: 203.x.x.2 Obviously this only trys to authenticate against the first server. Is there a way to tell Perdition that if authentication fails on server 1, try to auth against server 2? TIA. Cheers Nick Brown.