Structure and Function
The Hornetsecurity Email Continuity Service stores incoming and outgoing emails affected during an outage of your own mail server for a period of three months. During this time, it provides an alternative platform for sending and receiving emails in the form of the webmail client.
This guide will help you with the basic configuration of the Email Continuity Service and provide the most important information about its use.
Figure 1 shows a schematic representation of the system structure and the path taken by incoming emails
through the system. The system has two operating modes:
- Normal operation
- Emergency operation in the event of a disruption
During normal operation, after passing through the Hornetsecurity email gateways, emails are delivered to the recipient's regular email server, which makes them available to the recipient.
In the event of a disruption, emails are delivered to the Hornetsecurity Email Portal instead of the recipient's email server. The recipient can retrieve them there via POP or IMAP or, alternatively, manage them directly
in the portal's webmail interface.
After switching from emergency operation back to normal operation, all emails remaining in the inbox of the Hornetsecurity Email Portal are automatically delivered to the recipient's email server and deleted from the inbox in the Hornetsecurity Email Portal. Emails that were removed from the inbox during emergency operation (e.g., deleted or moved to other folders in the mail client) are not delivered again.
Important: Emergency operation can be activated and deactivated manually or automatically. If activation and deactivation are to occur automatically, this must first be configured by
Hornetsecurity Support.
In parallel with delivery to the recipient's email server or the Hornetsecurity Email Portal, copies of all delivered emails are sent to the Hornetsecurity Email Archive, where they are stored for
90 days. The same applies to all outgoing emails, provided that the customer's email server sends them via the Hornetsecurity email relays.
Users can retrieve emails in the archive at any time, whether during normal operation or emergency operation, and have them delivered again to the email server that is currently active.
Basic Configuration
You activate the Hornetsecurity Email Continuity Service in the Email Security → Continuity Service section.
Once the service has been activated, it can be configured for all users of the domain or only for specific mailboxes.
Important: If the Continuity Service is to be used for the entire domain, all email addresses in the domain must be created in the Control Panel before emergency operation is activated. Otherwise, the system will reject emails sent to email addresses that have not been entered during emergency operation. (During normal operation, recipient verification is performed by the recipient's email server.)
If you want to activate the service for individual users, select the email address for which the Continuity Service is to be used from the list, if necessary, and add it. As soon as you confirm these entries by clicking “Save,” the Continuity Service is active for the selected mailboxes.
Important: To store outgoing email traffic in the archive, outgoing email traffic from your mail server must be routed through Hornetsecurity as an email relay or “smarthost.”
Retrieving Archived Emails via the Control Panel
After the Continuity Service has been activated, emails are stored in the Hornetsecurity Email Archive for 90 days. Administrators can find them in the Control Panel and subsequently deliver them to the user again. If sending via Hornetsecurity has also been configured, outgoing emails can also subsequently be delivered from the archive to the sender.
Users logged in to the Control Panel can search for and view their own emails in the archive search in the Control Panel workspace and subsequently deliver them to their inbox again.
Automatic Switchover
If the destination server cannot be reached, delivery is immediately and automatically redirected to the Continuity Service server, which also makes the emails available via webmail access.
Unavailability is detected if the destination server cannot be reached (timeout) or responds to a delivery attempt with a 400-level error message. This can be seen accordingly in the SMTP code of the emails in Email Live Tracking:
example.server.com; 451 4.7.0 Temporary server error. Please try again later
continuityservice;444 Redirect because: (...)Example SMTP code during a delay and the Continuity Service taking over
Retrieving Mail During a Server Outage
During emergency operation, users can view and manage emails that have been transferred to the Continuity Service via the webmail client. For more information about logging in, please see the following article in our Knowledge Base: Logging In to the Webmail Client
Important! For users who log in to the Control Panel with their Microsoft 365 or LDAP credentials, the emergency password is required to log in to the webmail client.
Retrieving Mail via Your Own Email Client
As an alternative to the webmail client, you can also use your own mail client to retrieve emails from the Continuity Service if your mail server experiences an outage.
To do so, set up an additional POP3 or IMAP mailbox in your mail client using the following connection details:
Security and Authentication:
Connection security: STARTTLS
Authentication method: Password, normal
Inbox:
- IMAP server: imap.antispameurope.com - Port: 143
- Alternatively, POP3 server: pop.antispameurope.com - Port 110
Outbox:
- SMTP server: smtp.antispameurope.com - Port: 587
In your email client, always enter the full username (your own email address) and observe capitalization. To authenticate with the servers, use your corresponding credentials (emergency password, if applicable).
As already described, when your mail server becomes available again, emails are automatically delivered to this server and removed from the inbox of the email webmail client.