Two special configuration queries, multiple ips and global catchall

Hey Zhang, mostly directed at you;
Two queries,

I have two IPs, I would like mail from one domain sent from Primary IP and mail from all other domains send from the Secondary IP,
how would I go about setting this up?

The other, is there any way to set up a Global Catchall? Like postmaster@primary.domain would catch any e-mail that hit my server? Or a default domain sort of set up, so all e-mails that don't match a domain will match this default domain, and if the mailbox doesn't exist then it would use that domain's catchall?

Thanks in advance