Time Machine Backup Trying to Access Windows Exchange

I have an iMac that used to have access to a Windows Exchange email account. That email account has now been deleted as it caused too many conflicts. However, when I now access Time Machine my iMac tries to reconnect to the old Exchange server with an old password and that locks me on the Exchange email account as I assume it keeps attempting multiple logins. Unfortunately I dont have control over the Exchange account so I have to have that reset everytime I use iMac Time Machine. Is there ay way around this? Many thanks