StrataMail Backup MX Services
Your customers' mail doesn't bounce. Even when their server does.
StrataMail Backup MX Services accepts and queues inbound email the moment your primary mail server goes down. No bounced messages. No delivery failures to the sender. No manual intervention. When your server comes back, everything in the relay queue delivers automatically.
Need webmail access during outages? → See StrataMail Email Continuity
What StrataMail Backup MX Services Does
StrataMail Backup MX Services is a queue-and-redeliver service. It is the safety net under your mail infrastructure — invisible during normal operation, active the moment something goes wrong.
When your primary mail server is unreachable — whether from a hardware failure, maintenance window, network outage, or ISP issue — inbound mail continues to arrive. Without backup MX, those messages bounce. With StrataMail Backup MX Services in place, every message is accepted, queued in the relay queue, and held for up to 30 days. Senders never see an error. When your server comes back, the relay queue drains automatically.
What it is
- DNS secondary MX — lower-priority MX record for the domain
- Queue-and-redeliver — accepts, holds, and redelivers inbound mail after recovery
- 30-day relay queue retention
- 5-minute retry interval once primary recovers
- Compatible with any SMTP-reachable primary mail platform
- Per-domain pricing — no per-user fees
What it is not
- Not a webmail service — users cannot read or reply during an outage event
- Not a spam filter — SpamWeeder Premium is available as a separate add-on
- Not the primary MX — only activates when the primary is unreachable
- Not a shadow mailbox — no local copy stored for user access
If read and reply access during outage events is required, see StrataMail Email Continuity — which adds a shadow mailbox and branded Roundcube webmail access on top of the relay queue.
How It Works
- Normal operation — Inbound mail flows to your primary mail server. StrataMail Backup MX Services is idle.
- Primary goes down — Sending mail servers detect that the primary MX is unreachable and automatically fall back to the lower-priority StrataMail MX record.
- StrataMail accepts the mail — Every inbound message is accepted and placed in the relay queue. Senders receive a normal delivery acknowledgment — no bounce, no error.
- Relay queue holds for up to 30 days — Mail is stored securely and retried every 5 minutes once the primary becomes reachable again.
- Primary recovers — StrataMail detects recovery and automatically flushes the relay queue. All held mail delivers to the primary server in order. No manual steps required.
When StrataMail Backup MX Services Protects You
- Server hardware failure — disk failure, power issue, or component failure on your mail server
- Planned maintenance windows — server updates, migrations, reboots — schedule downtime without mail loss
- ISP or network outage — upstream connectivity failure between the internet and your mail server
- Data center incidents — power events, cooling failures, or facility issues affecting your server
- Microsoft 365 / Google Workspace disruptions — when the cloud platform itself has a service incident
- M365 tenant-to-tenant migrations — StrataMail catches inbound mail during the DNS propagation window when mail can arrive unpredictably at either tenant. Learn about M365 migration coverage →
- Hosting provider issues — cPanel, Plesk, or shared hosting environments experiencing outages
Supported Primary Mail Platforms
StrataMail Backup MX Services works with any SMTP-reachable primary mail server, including: Microsoft 365 (Exchange Online), Google Workspace (Gmail), Microsoft Exchange (on-premises), cPanel / WHM, Plesk, Zimbra, Postfix, Sendmail, Exim, Kerio Connect, and any SMTP-compatible mail platform.
Optional Add-On — SpamWeeder Premium
StrataMail Backup MX Services can be paired with SpamWeeder Premium spam filtering. SpamWeeder is configured as your primary MX — it filters inbound mail before delivery to your primary server, and uses its native multi-destination delivery to route to StrataMail when your primary is unreachable.
Adding SpamWeeder Premium means your inbound mail is filtered even during the backup MX window — queued messages were already scanned before being held in the relay queue. Learn about SpamWeeder Premium →
StrataMail Backup MX vs. Full Email Continuity
Not sure which product fits your situation? Here is the key difference:
| StrataMail Backup MX Services | StrataMail Email Continuity | |
|---|---|---|
| Mail queued during outage event | Yes | Yes |
| Mail redelivered on recovery | Yes | Yes |
| Webmail access during outage event | No | Yes — branded Roundcube |
| Read email during outage event | No | Yes |
| Reply and send during outage event | No | Yes |
| Shadow mailbox (local copy) | No | Yes |
| SpamWeeder Premium add-on available | Yes | Yes |
| Per-domain pricing | Yes | Yes |
| Best for | Queue protection — outage event is invisible to senders | Business continuity — users stay productive during outage event |
See full comparison → | See StrataMail Email Continuity →
Reseller & MSP Program
StrataMail Backup MX Services is built for resellers. MSPs, hosting providers, and IT consultants can add backup MX protection to every customer domain — under their own brand, with their own pricing, from a single reseller account.
- White-labeled admin control panel — your branding, your logo
- Per-domain provisioning — add and manage customer domains through the portal
- Usage dashboard — monitor domain status, relay queue depth, and relay activity
- Outage alerts — email and SMS notifications when a customer's primary goes down
- Branded alert emails — alerts sent from your address, not ours
- Volume pricing — deeper discounts at higher domain tiers
- Dedicated reseller support channel
Reseller tiers start at $29.99/month for up to 5 domains — effective $6.00/domain.
View Reseller Pricing → | Learn About the Reseller Program →
Direct Customer Pricing
Not a reseller? StrataMail Backup MX Services is available directly at a per-domain rate with no platform fee and no volume commitment.
- $12.00/domain/month — includes 30-day relay queue retention, monitoring, and outage alerts
- One-time setup fee: $125/domain
- SpamWeeder Premium add-on: +$9.00/domain/month
Protecting 5 or more domains? The reseller Starter tier at $29.99/month is a better value. See the comparison →
