Is there a way to 'favourite' or 'star' a regularly used contact/customer email?

Is there a way to 'favourite' or 'star' a regularly used contact/customer email?

Hi knowledge base, 

We have a huge customer base, many of who will only ever use Zoho once. However, I am often forwarding to one or two external emails. Some of those names are so buried in the weeds that I need to spell out the entirety of their email before I can find them.

Is there a way to mark them as 'favourite' kinda like you do in a phone contact list.

Have a better one,
Chris