Office 365

Hey guys, I have a situation here, and I'd like to get some help.
Now, I have been tasked with implementation of Office 365 E3. And the organization has an existing domain hosted at the mother company. However, they want to migrate to a new domain without necessarily breaking away from the mother company(as they may be seen as rebels). Is it possible for this to happen ?

And for user who had existing outlook mails, is it possible to add them as users.

Moreover, If you may, kindly provide the things I need to look out for during the installation.

Looking forward to your positive responses.

Thanks.

Since Office 365 is subscription based I'd ask what the effect on that would be if not working with the mother company's domain such as having to purchase again. Don't know why 2 network adapters for 2 domains couldn't be used.

Kindly elaborate further.

Which part do you need elaborated on?

you have said you don't know how using a two network adapters on two domains will affect it, .. I haven't understood what exactly you were driving at in that point.

Unregard that.