One too many login IDs

I can log into my business email using both my business email address (hosted on Zoho) and my personal email address (not). They seem to be tied together like aliases, as my personal address logs me in as if I had used my business address. My personal email address is not an email user not does it seem to appear anywhere else. I don't know if this situation is normal, but I prefer my personal email address not be associated with my business account.