Hi,
Luckily, I used to work on EV so I can probably help here but really need to know what you need to achieve?
Enterprise Vault can archive email in two main ways:
1. Via the journal mailbox: With Exchange, the journal mailbox contains copies of EVERY inbound message. EV will archive everything from this using the EV Journal Connector.
2. Via specific mailbox archiving: You can configure SBG to send a copy of every mail (or mail destined to specific addresses, or messages with a specific header or subject or content in the body or whatever) to a specific mailbox in your environment and then configure EV to archive the mail from that account.
If you can let me know what your overall goal is, I can probably help you a little more or put you in touch with someone from EV who can help.
//ian