Package 1 · Backup MX
Secondary MX, temporary queuing during destination outages and automatic delivery on recovery. No mailbox pre-check, AntiSpam, Antivirus, content inspection or quarantine.
TECHNICAL GUIDES
Backup MX with Multiple Primary Mail Servers
Plan secondary routing for several legitimate primary destinations without loops or extra domain subscriptions.
Package 2 · Email Protection
Primary MX gateway with configurable AntiSpam, Antivirus, sender-domain checks and quarantine. Publish only gate.securawall.com and configure a separate manual receiving target. Queuing and recovery remain included.
Optional SMTP Relay add-on
Add authorized outbound delivery to either Package 1 or 2 for the same domain. Separate add-on pricing, approval, server credentials, quotas, TLS and verified SPF apply. Customer-domain DKIM signing is optional and recommended. Incoming protection remains determined by the base package.
Explore packages and add-ons
By the SecuraWall team · Updated · Operational guidance, not a delivery guarantee.
One domain, several receiving targets
A domain can publish several legitimate MX targets. They may represent preference tiers or equivalent servers. They are not separate SecuraWall subscriptions: the unit of the Backup MX plan is the domain. Your receiving servers remain responsible for valid recipients and consistent mailbox delivery.
Review the complete preference set
List all intended primary targets and their preference numbers. Place the secondary gateway after the intended primaries. Do not assume that the first row returned by a DNS tool is the only primary. Equal-preference targets need a receiving design that tolerates either being contacted.
Choose automatic or manual delivery
SecuraWall automatic mode discovers eligible primary MX destinations and excludes its gateway. Automatic routing uses safe public destinations and SMTP port 25. IPv4 remains available; IPv6 delivery requires activation on the gateway. A public AAAA record alone does not mean IPv6 delivery is enabled. Manual mode selects one configured public target and port; it is not a multiple-target failover list.
Do not hide receiving inconsistencies
A server returning unknown-recipient or a permanent policy error is different from a server that cannot be reached. Fix directory, relay or security-policy mismatches at the receiving layer. The backup route should not be used to bypass a legitimate rejection by searching for a more permissive server.
Test each intended path
Use an authorized recipient and record the destination reached. In a controlled maintenance window, test a temporarily unavailable primary and subsequent recovery. Confirm DNS changes, saved automatic targets, queue age and receiving logs. Separate hostnames alone do not prove replicated data or independent infrastructure.
References and service conditions
Related guides
MX Priorities and Multiple Mail Servers
Understand preference numbers, equal-priority records and secondary MX placement.
Read guide →Backup MX with Microsoft 365: Evaluate the Mail Flow
Check whether a secondary SMTP route fits your tenant and what receiving configuration must be validated.
Read guide →Backup MX with Google Workspace: Plan Before Adding MX
Evaluate secondary routing, forwarded-mail authentication and receiving policies without assuming universal compatibility.
Read guide →