Run high-volume email delivery on infrastructure your team controls.
Deploy Momentum on your own bare-metal servers, private data centers, or cloud VMs when security, data residency, or custom routing rules require an on-premises MTA. Handle millions of messages per hour with Lua-scriptable policy hooks, automatic per-ISP throttling, and full control over your queues and IP pools.
Momentum
A programmable delivery path
Messages from your applications
Process
Apply your message-processing workflow.
Apply policy
Choose routing and delivery behavior.
Deliver and adapt
Respond to receiving-server conditions.
Adaptive Delivery
Delivery responses inform sending behavior.
Architecture illustration. Your team operates the infrastructure and configures processing, policies and delivery for its requirements.
Built for high-throughput, policy-driven mail operations.
Keep message generation, queue management, and SMTP delivery inside your own network while adapting to mailbox provider rate limits in real time.
Internationalized email headers (SMTPUTF8)
Deliver to local-language email addresses and include non-ASCII characters in headers and recipient domains without breaking standards compliance.
Custom policy and routing rules
Write policy hooks to inspect, modify, route, or reject messages at every stage of the SMTP conversation based on your internal business logic.
TLS transport and authentication
Sign outbound mail with DKIM, align SPF and DMARC, and enforce opportunistic or required TLS encryption across every outbound connection.
Multi-threaded queue architecture
Process bursts of transactional alerts and multi-million-recipient broadcasts concurrently without letting slow destination domains block fast ones.
Traffic segregation and virtual MTAs
Isolate password resets, billing notifications, and promotional broadcasts onto separate IP pools and queues so each stream keeps its own reputation.
Live SMTP telemetry and bounce classification
Stream real-time delivery logs, deferral reasons, and bounce categories into your monitoring stack so operators can spot ISP blocks immediately.
Adapt to mailbox provider rate limits automatically.
Every mailbox provider pushes back differently, throttling connections, deferring messages, or rejecting mail when volume spikes or engagement dips. Momentum watches live SMTP responses and adjusts delivery parameters on the fly: backing off concurrent connections when a receiver slows down, queuing deferred mail for retry, and pausing a stream until a temporary block clears. You protect your sender reputation without babysitting per-domain rate tables, using the same adaptive delivery discipline that powers the hosted Bird Email API.
Deploy on bare metal, private cloud, or a hybrid topology.
Run Momentum entirely inside your own data center to satisfy strict data-residency or regulatory mandates, deploy it on cloud instances close to your application tier, or split your architecture across both. You can keep sensitive message assembly and recipient data on-premises while bursting peak campaign traffic through cloud relays, without locking your operation into a single hosting environment.
Questions about Momentum MTA
What is Momentum MTA?
What is Adaptive Delivery, and how do I monitor it?
Can I run Momentum in the cloud, and is it still being developed?
Connect on-premises MTA delivery to the wider email platform
Scale without
losing control.
Organize teams in workspaces, control API access, and trace changes through audit logs.