Email MIgration

Email MIgration

I have an existing domain that has only one email account. I am trying to migrate that one email account to Zoho. I set up the domain on Zoho, created a new username to be the Admin, created new MX records to point to Zoho servers and created the required TXT records. I am receiving email under the new Admin email address at Zoho mail. But I am having trouble figuring out how to migrate the existing email account for that domain. I think that I have to set up the User first before I can add the User to the Migration. But since this is an existing email address, I don’t want to create a new user. I tried to do 'Invite a User with other existing email address' and it says that the the user was already invited. But since I am no longer receiving email for this domain in my old mail client, I cannot retrieve the email invitation to accept it.  How do I get this User added to Zoho under the existing user name?