Switching domain in office365 without buying additional license and keeping exchange mailbox

I have Microsoft office 365.com P1 account with 2 mailboxes.  And here is my question/problem.

I have two users total in this account:

 lets call them bill@acmellc.com and steve@acmellc.com

both with big 10 plus Gigabyte office 365 P1 plan mailboxes.
 So to recap, two users with two licenses.  
For legal reasons they have to change there domain name to bill@acme.com and steve@acme.com.  basically dropping the "LLC" out of there domain name.

Is there a way I can add the new domain to the office 365 P1 account and feed the existing exchange boxes with the mail from the new domain without adding additional office 365 licese's ane without creating new mailboxes?   Then I will need to create forwarders out of the old addresses, so that mail sent to the old address:  bill@acmellc.com forward to bill@acme.com.  So will office 365 P1 plan let me do this
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

Vasil Michev (MVP)Commented:
Just add the domain and verify it, then set it as Exchange Online domain. Once you have done this, simply add additional Email aliases associated with the new domain to the users in question, and if needed also adjust the primary SMTP address. You can have dozens of domains listed and dozens of email addresses associated with the same user, no additional licenses are required. No forwarding will be necessary also, as it will still be the same account, same mailbox.

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
Adam BrownSr Solutions ArchitectCommented:
Vasilcho is correct. You can have as many domains as you want and as many email addresses as you want on any account. The limitation is whether or not you want users to be able to respond using multiple email addresses. If there is a reason for a user to respond to some user and have recipients see the address as bob@acme.com for some and bob@acmellc.com as others. In this situation, you would create a shared mailbox for the second address, grant full access permission on it for the user's main mailbox, then set up forwarding so the emails sent to the additional address are forwarded to the main mailbox. Shared mailboxes do not require licenses, but are limited to 5GB and cannot have any advanced features attached (In-place hold, archives, etc.).
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Office 365

From novice to tech pro — start learning today.