I want to setup my Google Apps to take iCloud emails

I have a Google Apps email account with personal domain, and I have an iCloud account. I want to be able to setup the DKIM/SPF or CName on my Google Apps (or domain manager) so that if i send an email via iCloud using my Google outbox SMTP, it will show up on the recipient as from [email protected] rather than [email protected].

If someone can give me some guidelines as to the settings and steps I need to take, that would be great.

thanks!