ICANN (The Internet Corporation for Assigned Names) implemented a new Transfer Policy which came into effect on 1st December 2016. As per the new policy, upon modification of the email address, the current and the new Registrant has to authorize this change by clicking on the link received on the current and new email address.
Once you click on the link, the domain will be successfully verified.
Since the current Registrant is unable to access the email address "firstname.lastname@example.org", I would request you to kindly provide us with the following documents so that we make the changes on your behalf.
1) A valid Government issued Photo ID proof of "EAC Limited" bearing the signature in it (e.g: Passport or ID)
2) Company proof for "eacdirectory" (Certification of Incorporation, Government Issued Registration Certificate/Document)
3) Contact modification form to be filled and manually signed by the Registrant - EAC Limited (these can be downloaded from any of the below formats). Please note that the signature on the form and the Photo ID proof should match.
Registrant has to authorize this change by clicking on the link received on the current and new email address.