When your primary mail server goes down, two problems need solving simultaneously. First, inbound messages need to be captured so nothing is lost — that is what StrataMX Backup handles. Second, your users need to keep working, because in most businesses "email is down" is not an acceptable status for hours at a time. StrataMail Email Continuity solves the second problem — and handles inbound protection at the same time.
Continuity vs. MX Backup: The Key Difference
StrataMX Backup is a passive service: it queues inbound email while your primary server is unavailable and delivers everything on recovery. Users cannot read those queued messages during the outage, and they cannot reply to them. Email is preserved but inaccessible until the primary comes back up.
StrataMail Email Continuity is an active service. Every message that arrives during the outage is stored in a continuity mailbox the moment it arrives. Users log in to branded webmail, read new inbound messages, reply, and send email normally from any browser. Email keeps flowing — in both directions — throughout the outage.
How StrataMail Continuity Works
StrataMail Email Continuity does two things at once for every message that arrives during an outage:
- Shadow mailbox — immediate access. The message is stored in the user's continuity mailbox in real time, so it is already waiting when the user signs in to webmail.
- Relay queue — automatic recovery. The same message is queued for delivery to your primary mail server, retained for up to 30 days, and retried every 5 minutes once the primary is reachable again.
Mail usually reaches StrataMail through your spam filter. With SpamWeeder Premium as your primary MX, its multi-destination delivery routes to StrataMail automatically when your server is unreachable — no DNS change. With Proofpoint, Mimecast, Barracuda, Microsoft Defender, or another filter, StrataMail is set as the filter's alternate delivery destination. Without a filter, StrataMail can sit as a lower-priority MX record, which gives queue protection only, without webmail access. The service works with any SMTP-reachable mail platform: StrataMail, Microsoft 365, Google Workspace, on-premise Exchange, and others. DKIM signatures on relayed messages are preserved.
What Users Experience During an Outage
- StrataMail begins accepting inbound mail immediately — senders see no bounces and no errors.
- Users are notified, by their IT team or by StrataMail's outage alerts.
- Users open the webmail portal, branded with your company's or your provider's identity, from any browser on any device.
- Everything that arrived since the outage began is already there. Users read, reply, and send normally.
Users who live in a desktop client like Outlook will notice the switch to the browser. Users who already use webmail or mobile access find the transition easy. In every case, the critical business function — the ability to communicate by email — continues.
Recovery: The Relay Queue Delivers
When your primary mail server comes back online, StrataMail detects the recovery and flushes the relay queue automatically — every message received during the outage is delivered to the primary server in order, with no manual steps. Replies and new messages sent from webmail during the outage were already delivered to their recipients at the time they were sent. The admin dashboard shows queue depth, delivery status, and the event log throughout, so your IT team can see exactly what arrived and when.
Automatic Failover Through Your Filter
StrataMail Email Continuity does not wait for anyone to flip a switch. Your filter routes mail to StrataMail as soon as your primary server stops answering, and StrataMail's monitoring opens an outage event and sends alerts to the addresses you choose. By the time your team is aware there is an outage and beginning to investigate, inbound mail is already landing in the continuity mailbox.
Who Benefits Most
- Customer-facing teams — sales, support, account management — where email downtime directly delays customer response
- Organizations on Microsoft 365 or Google Workspace — who otherwise have no fallback when the cloud platform has an incident
- Organizations running on-premise mail servers — where hardware failures and maintenance windows create meaningful downtime risk
- Businesses with contractual email availability commitments — where demonstrable uptime matters beyond internal operations
- Professional services firms — law, accounting, consulting — where email is the primary client communication channel
StrataMail Email Continuity is priced per domain, for direct customers and for resellers who offer it under their own brand. See StrataMail Email Continuity at Infinity Data Center for pricing, contact Infinity Data Center, or call 866.790.4678 to add continuity to your domains.