Messagelabs question

Hi,  Apologies in advance for this simple question but I dont have access to a MessageLabs console to confirm.  My customer currently has one Exchange 2003 server routing mail to\from messagelabs.  They will be replacing it with two Exchange 2010 transport servers for inbound\outbound smtp.  Is there a best practice for setting them up in MessageLabs?  i.e. support for more than one inbound gateway, using a separate external IP address for each transport server etc.?

Thanks in advance,

Steve