NetSuite hardware maintenance

RE: As a courtesy, this communication is to notify you of scheduled downtime for your NetSuite account(s) during a planned maintenance window as we perform hardware maintenance.

Account xxxxxxx is scheduled for maintenance downtime on August 30, 2021 from 1:00 am to 4:00 am (Mountain Standard Time).

You will be unable to access the following on your account: accounts, online forms, Web sites and Web stores during this time. Please note that the downtime may extend beyond the scheduled time if unforeseen complications arise during the maintenance process. All practical measures have been taken to prevent this, but the possibility does exist.

Question: Clients not being able to access customer center. If they do send an email to us (to create a case) for support during the downtime, the email is just "queued" up and then once system is back up it will be received/captured as normal right? It would not be rejected back to the client. Correct understanding?