keeping emails on different domains separate

keeping emails on different domains separate

I have a modest 1 user paid Zoho account ( 31262929 ) which I thought allowed me multiple domains (though only one user)

I have moved 2 domains to Zoho Mail.
hostedcycling.com
and
ensemblecycling.com

I am trying to setup my Zoho Mail for these two domains and then offline IMAP email accounts on Thunderbird.
but I want to keep the email addresses separate and distinct.
right now, all mail to either account seems to come into both.

can you help me sort this out?