Email bounces are automatically processed by Lead Liaison. After processing your emails, subscribers will be marked appropriately, and you can access all bounce related statistics from the Statistics > Email Campaign Stats or Statistics > Contact List Stats pages.
Hard bounces will mark a Subscriber as "Bounced" by the application after one bounce, and deal with problems like "email address doesn't exist" or "invalid domain name". Soft bounces take 5 times to remove a subscriber from your list, and deal with more common problems like "relay problem" or "mailbox is full".
Lead Liaison also has a process to configure DKIM/DomainKeys, SenderID and will support you when setting up your SPF record.
