message streams

Separate transactional and marketing email with Message Streams.

Every email has a different job. When password resets share a pipeline with promotional blasts, one spam complaint can block critical receipts. Message Streams split your SMTP traffic into isolated paths — each with its own domains, analytics, and webhooks.

Your app / CRM SMTP + API SMTPServer Message Streams router Transactional Receipts, 2FA, alerts Dedicated IP, clean path Inbox Marketing Newsletters, campaigns Secondary domain pool Stream analytics Alerts Bounces, webhooks hard_bounce to your API Real-time webhook

What are Message Streams?

Message Streams are dedicated sending pipelines inside SMTPServer. Each stream routes a type of email — transactional, marketing, onboarding, or alerts — through its own domain pool and reputation path. If a marketing campaign spikes bounces, your transactional stream keeps delivering without cross-contamination.

Mixed pipeline

One SMTP path
Marketing blast
Spam folder
Password reset
Blocked too

Message Streams

Stream router
Transactional Inbox
Marketing Isolated stats
Alerts Webhooks
Critical mail keeps delivering

Mixed traffic drags everything down. Isolated streams protect the mail that matters most.

Why should you separate transactional and marketing email?

Mixed traffic is the fastest way to lose inbox placement for the messages that matter most.

Protect critical sends

Receipts, 2FA codes, and password resets stay on a clean transactional stream — isolated from high-volume promotional sends.

See what actually performs

Stream-level stats show sent volume, delivery rate, and bounces per pipeline — not a blended average that hides problems.

3 Built-in stream types
1+ Domains per stream
€39 Dedicated IP plans from

Stream-level analytics in your dashboard

Track delivery trends, outcome splits, and domain pool performance for each message stream — without mixing transactional and bulk data.

SMTPServer Message Statistics dashboard showing total sent, delivery rate, bounce rates, daily delivery trend chart, outcome split donut chart, and domain pool performance bars for a bulk sending stream.
Delivery analytics for message stream domain pools — filter by stream, date range, and timezone.

How do Message Streams protect deliverability?

Multi-domain flexibility

Map one or many domains to a single stream. Run a SaaS app and agency clients from one account with clean, branded sender signatures.

Stream segmentation

Create streams per segment, campaign type, or department. Keep transactional mail on dedicated IPs separate from newsletters.

Precision analytics

Compare onboarding vs weekly digest streams side by side. Spot bounce spikes and complaint trends before they spread.

Real-time webhooks

Trigger automations when a stream reports a bounce, complaint, or click. See API integration for webhook setup.

How do you set up a Message Stream?

1

Create a stream

Name it for the traffic type — transactional, marketing, or alerts.

2

Map domains

Attach one or more verified domains to the stream's pool.

3

Route traffic

Point SMTP or API sends at the stream-specific credentials.

4

Monitor analytics

Review delivery stats and webhooks per stream in the dashboard.

Who benefits from Message Streams?

If you are…The challengeHow streams help
SaaS founder Password resets land in spam because they share an IP with outreach campaigns. Create a Transactional Stream for app alerts and a Marketing Stream for product updates.
Growth marketer A/B test campaigns risk your primary domain reputation. Map a secondary domain to an Outreach Stream with its own analytics.
Developer Hard bounces should pause user accounts automatically. Configure a webhook on your Alerts Stream — catch hard_bounce events in your backend.

Common questions about Message Streams

Can I attach multiple domains to one stream?

Yes. Map one or many verified domains to a single stream for branded sending across business units — see multiple domain setup.

Do Message Streams have separate analytics?

Each stream reports sent volume, delivery rate, bounces, and domain pool performance independently in the dashboard.

How do webhooks work per stream?

Add HTTPS webhook URLs in the dashboard. Events like bounces, complaints, and clicks fire only for traffic in that stream.

Are Message Streams included in all plans?

Stream segmentation and analytics are available on paid plans with dedicated IPs. Start on the free plan to test SMTP, then upgrade on plans.

Reclaim your inbox placement.

Split transactional and marketing traffic into Message Streams — quick DNS setup, transparent EUR pricing, and chat support when you need it.

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