Throughput · sending infrastructure
Mumara Campaigns connects to every major SMTP gateway and API service, distributes load across as many servers as you operate, runs concurrent worker threads tuned to each mailbox provider, and ships with PowerMTA as a first-class addon. Built for senders who count in millions.
12,840
in flight
48
workers
5.2K/m
delivered
Gateways · rate · status
Four pillars of high-throughput sending
Email at scale isn't about one fast button. It's about the configuration surface beneath it — gateways, throughput, authentication, and the PowerMTA path for the high-volume tier.
SMTP servers, API services, and PowerMTA — all configurable as Sending Nodes. Add as many as your sending stack requires. Group them. Route per-broadcast.
Each node runs concurrent worker threads. Multiple servers run in parallel. The queue drains at the rate your sending IPs and provider tolerances allow — not bottlenecked by a single thread.
SPF, DKIM, DMARC verification for every sending domain — with real DNS checks, not a "trust us" toggle. Domain status is visible in the dashboard with PASSED / PENDING / FAILED.
For high-volume senders running PowerMTA, the addon adds first-class integration — auto-generated nodes, DNS keys, bounce handlers, SSH-pushed config. No glue scripts required.
Sending Node configuration
Each Sending Node is a complete delivery configuration — gateway type (SMTP / API / PowerMTA), authentication, encryption, sender identity, tracking domain, custom headers. Mumara's Validate Connection button tests credentials before save; Send a Test Email confirms end-to-end delivery before you ever commit a real broadcast. Mistakes caught at setup, not at scale.
Pick the gateway type. SMTP for self-hosted relays and most managed services; API for partners that expose a HTTP send endpoint; PowerMTA for the high-volume tier via the addon.
Nodes group together (e.g., "smtp group", "pmta group") so Mumara can route specific broadcasts to specific gateway pools. Useful for separating transactional and marketing traffic.
Attach a tracking domain to each node for click-redirect and open-tracking links. Means your tracking URLs share the same brand as your sender domain — better deliverability, better trust.
Validate Connection and Send a Test Email buttons live on the node config screen. You verify credentials and end-to-end delivery before pointing a real broadcast at it.
Sending Domains · SPF / DKIM / DMARC
Every Sending Domain you add to Mumara gets verified against real DNS records — SPF, DKIM, and DMARC — with explicit status pills (PASSED, PENDING, FAILED). When a domain fails, Mumara tells you why; when it passes, mailbox providers reward you with better inbox placement. The Auto DNS addon takes this one step further: configure once, Mumara pushes the right records to your DNS provider automatically (CloudFlare, Route53, Hetzner, and more).
PASSED / PENDING / FAILED based on actual DNS lookups. When DKIM fails, you see the specific selector and key that didn't match.
Each sending domain has its own tracking prefix and redirection type (cname / 302) so click and open URLs match the brand of the email — not a generic tracker.com domain.
Configure as many sending domains as you operate — different brands, regions, programs. Each authenticates independently; Mumara honours per-domain reputation.
Don't want to manage SPF/DKIM/DMARC records by hand? The Auto DNS addon pushes them to your DNS provider directly. Supports the major registrars; one-click installation per provider.
Two paths to high-throughput
Most senders start with SMTP/API gateways — the partners are everywhere, the config is straightforward, and Mumara connects to all of them. When volume justifies it, PowerMTA via the addon adds another tier.
Start here
Connect to every major SMTP gateway and API-based sending service. Configure as many nodes as you need; group them by purpose; route campaigns by group. The path most senders use — and the only path needed for most volumes.
High-volume tier
When SMTP partners can't keep up with your volume, PowerMTA is the answer. Mumara's PowerMTA addon adds first-class integration: auto-generated sending nodes, DNS keys, bounce handlers, and PMTA config pushed via SSH. No glue scripts.
Why Mumara senders scale
What undersized sending infrastructure costs
Sending a million emails isn't a single command — it's a thousand thousand-email operations, each in parallel, each respecting different rate limits, each with its own authentication and tracking. Mumara is built for the architecture; most ESPs hide it from you and hope you don't notice.
If your ESP routes everything through one SMTP partner, the day that partner has an outage or a deliverability drop is the day your campaigns stop. Mumara's multi-gateway architecture means a routing failure on one path doesn't take everything down.
A serial queue can only go as fast as one connection. Mumara's per-node thread pool fans out parallel deliveries to the receiving MTA's tolerance — not a single thread's pace.
Mailbox providers in 2026 require SPF + DKIM + DMARC for any volume sender. Without verified records, your inbox placement collapses regardless of content quality. Mumara's domain-verification flow makes this configurable, not opaque.
When a node has connectivity issues or a domain's auth fails, you need to see it immediately — not in a support ticket three days later. Mumara surfaces node Error states and domain verification failures directly in the dashboard.
“We migrated from a black-box ESP that hid every sending decision. Mumara is the opposite — we see every node, every domain's auth, every server's queue. Our deliverability climbed within a month of switching.”
Verified review
Mumara customer
Common questions
A growing roster of major SMTP gateways and API-based sending services. The Sending Node Gateway dropdown lists every supported type at configuration time — connect with credentials, validate the connection, send a test, you're live. Mumara's integration list expands as the ecosystem changes.
PowerMTA is a high-volume MTA used by senders who push past what SMTP partners comfortably handle. Mumara's PowerMTA Integration addon adds first-class support — the dedicated '+ Add PowerMTA' button in the Sending Nodes view, auto-generated PMTA config including DNS keys and bounce handlers, and SSH-managed deployment. Paid addon, see the pricing page for current pricing.
Each sending node runs a configurable pool of concurrent worker threads. When a broadcast queues, Mumara's worker pool fans out parallel deliveries to the receiving MTA. The per-node thread count, throttle rules, and per-mailbox-provider rate limits combine to push at the rate the receiving side accepts — never faster (which would trip deliverability thresholds).
Yes — multi-server distribution is core to Swift Sending. The Sending Nodes page has both a Nodes tab and a Servers tab; sending servers group physical or virtual machines that handle delivery, and Mumara balances the queue across all configured servers automatically. Pause, resume, restart any individual server without losing messages from the queue.
Per Sending Domain. Add a domain in the Sending Domains view; Mumara performs real DNS lookups and reports verification status (PASSED / PENDING / FAILED) with explicit reasons for failures. The Auto DNS addon takes this further — for supported providers (CloudFlare, ClouDNS, Hetzner, Google Cloud DNS, Route53, Dynu, GoDaddy, DNS Made Easy) it pushes the required records automatically. See the pricing page for Auto DNS addon pricing.
Yes. Sending Nodes group together (e.g., 'transactional group', 'marketing group', 'pmta group'), and broadcasts can be routed to specific groups. Use this to keep transactional separate from bulk marketing, or to route region-specific traffic to region-specific infrastructure.
Queue durability is built in. If a node drops connectivity, its in-flight messages return to the queue and Mumara redistributes them to other available nodes in the same group. The campaign continues without messages being orphaned or duplicated. Restart the failed node and it rejoins the pool on the next poll.
Each Sending Node specifies its bounce-return path (the bounce address that receives MTA failure reports). The Bounce Addresses configuration is separate — see /campaigns/features/bounces-and-spam/ — and connects via POP/IMAP. Confirmed bounces flow back into Mumara's bounce processor for classification, and Hard bounces lead to suppression.
Related
The bounce/complaint pipeline that catches every delivery failure your sending infrastructure encounters.
Read moreThe downstream of bounces and complaints — suppression-list updates sync to every sending node every 15 minutes.
Read moreEvery broadcast routes through the Sending Nodes you configure here. Pick a group, send.
Read morePer-node, per-server, and per-broadcast delivery analytics — see which gateway delivered what, and how fast.
Read moreDrop-in PMTA support — auto-generated nodes, DNS keys, bounce handlers, SSH-pushed config. Addon.
Read morePush SPF / DKIM / DMARC records to CloudFlare, Route 53, and other providers automatically. Addon.
Read moreMumara Campaigns · Swift Sending
Sending Nodes, Sending Domains, and Swift Sending throughput ship with every Mumara Campaigns plan. The PowerMTA Integration and Auto DNS addons are separate purchases for high-volume and multi-domain setups. Free trial includes all addons — try the full infrastructure surface.
