I couldn't go to email section in Zoho CRM settings - permission is denied (I'm an admin)

I couldn't go to email section in Zoho CRM settings - permission is denied (I'm an admin)

I want to change my IMAP configuration in Zoho CRM. Go to setup->channels->email and error message popped up  -
Permission Denied
You do not have sufficient permissions to perform this operation. Contact your administrator.
But the thing is that I'm the administrator. Please help me to solve this.