Not knowing all the details, a specific answer could not be provided. And if the details are complicated, then you will probably not get the answer here on the AVVO forum. You will probably need to take everything to a local landlord-tenant attorney for a consultation.
Generally speaking, emails can be binding if they demonstrate that the parties had an agreement to the same terms. But, emails do not always create a binding agreement, and your lease may not allow for any provisions that are contained in the actual lease.