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 assign 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 mail server comes back online, you can still choose fetching emails at the selected mail boxes back to your mail server.