BHS-MM
You stop receiving all Tickets? Like, web submitted and email submitted? Or just emailed Tickets? If just emailed Tickets I'd highly suggest reviewing your Cron Job/Scheduled Task to ensure it's running all the time and not just during a certain timeframe.
The tickets are also not being created in the email inbox either.
Do you mean the emails aren't even in the INBOX? If so that would be an issue outside the osTicket software. I'd suggest reaching out to your mail admin/provider for further assistance if that's the case.
Cheers.