abc.com and xyz.com.

We've been using abc.com regularly for a year. But we want to switch the sender address to focus attention to our product site, xyz.com. Can we just make that switch on our next email blast, or do we need to take any steps to ensure our deliverability is as good as it should be?

We have been using our domain, abc.com, to authenticate emails. XYZ.com is also authenticated, but we have not been sending with it for many months. Do we need to IP warm or take other steps if we want to use that domain in our next campaign?