Yes, when your email server is down and will be remain down for some time. You can turn on the mail rescue mode for your domain at the Mail Backup Control Panel. Our system will assist you to create all email addresses under your domain and create corresponding mailboxes for each email address. Your emails queue up on our mail server will be forwarded to our mail rescue server instead. Every user fo the domain will be able to use our webmail or use POP3/IMAP to reach their emails and reply their emails.
After your email server comes back online, you should turn OFF mail rescue mode to avoid emails going to the rescue server.