ive bought zoho books for 1 year, do i have to buy mail hosting?

ive bought zoho books for 1 year, do i have to buy mail hosting?

i have five email accounts for my staff accessing zoho books. i had started using it on a trial basis then really liked it so i bought the 1 year package and got a discount for two months. however, im still getting prompts to upgrade my email accounts to a paid version! why is this happening?