replies to emails are sent to my gmail inbox, not my Zoho inbox. Why?

replies to emails are sent to my gmail inbox, not my Zoho inbox. Why?

For the past 2 days all of my email replies have been going to my gmail accounts inbox, as opposed to the Zoho inbox which is the account they were sent from.

Why is this?

Seems very very very bizzare!

What could I be doing wrong? Got a feeling its a stupid mistake.


Thanks in advance