e-mails not in contact list being converted to leads

e-mails not in contact list being converted to leads

A while ago I set this option:

-Have Zoho monitor my IMAP account...if I send an e-mail to someone who is not in our Zoho contact list, then create a lead automatically for therm.

I desire to turn this feature off, but I can;t fine where I enabled it....any ideas?

Thanks!