My website (contacts forms) use Zoho email address & got hacked

My website (contacts forms) use Zoho email address & got hacked

As a result I have received 11,000 (so far- in less than 2 hours) email notifications via my zoho mail - My developer has rolled back & cleaned the site) but emails seem to be still coming in batches. (Currently they seemed to have finally stopped) When I log into my Zoho Mail - None of these emails are there. I would like to go in and if at all possible delete them from the source. Or if there is a setting that will prevent these from coming into my mail client. (I use apple mail on my computer and am at this point afraid to open it.