Fixed - Outlook - This group of folders is associated with an email account

I am using Microsoft Office professional plus 2013. When I try to remove additional mailbox from my Outlook, I am getting the below error.

This group of folders is associated with an email account. To remove the account, click the File Tab, and on the Info tab, click Account Settings. Select the e-mail account, and then click Remove

I followed the same by going to File --> Info --> Account settings but I can see only the main mailbox email account. I am unable to find the additional mailbox account there. Any help would be greatly appreciated.