Keep Legacy and Modern Systems on One Reliable Relay
SMTP is still the fastest path for many apps, plugins, and internal services. Sendarix gives you production-grade SMTP handling with clear logs and event outcomes.
Use the same relay for transactional traffic, notification workloads, and platform-generated messages without adding fragile one-off tools.
Designed for Real SMTP Operations
This is not a basic forwarding layer. It is a controlled sending pipeline with authentication support, queuing discipline, and observability for operational teams.
Secure Submission
SMTP AUTH and TLS-capable submission flows for protected credentials and transport.
Throughput Stability
Consistent performance for burst traffic and daily background mail workloads.
Visibility & Logs
Investigate delivery outcomes quickly with searchable logs and event-level tracking.
Smooth Migration
Move from old SMTP providers without forcing an immediate full architecture rewrite.
Dedicated Sending Identity
Use authenticated domains and sender policies that align with enterprise mail requirements.
Queue-Aware Reliability
Protect delivery consistency during spikes with controlled queueing and retry behavior.
SMTP Relay Flow
A clear 4-step flow to keep infrastructure predictable and debuggable.
1. Connect
Application connects via SMTP credentials and establishes a secure session.
2. Accept
Message is validated and accepted into the queue for controlled processing.
3. Route
Traffic is routed through delivery paths with resilience and provider-aware behavior.
4. Track
Outcome events and logs provide operational confidence and faster troubleshooting.
Frequently Asked Questions
Can we start with SMTP and move to API later?
Yes. Many teams begin with SMTP for speed, then add API endpoints for deeper product workflows.
Do we get delivery-level visibility?
Yes. Logs and event streams are available so you can inspect accepted, delivered, and bounced outcomes.
Is this suitable for high-volume sending?
Yes. The relay is built for sustained traffic and burst events common in production platforms.
Which ports and encryption should we use?
Most production clients use submission on port 587 with STARTTLS, or implicit TLS on 465. Avoid cleartext SMTP on public networks.
Can we restrict SMTP to known IP addresses?
Yes. IP allowlisting is a common enterprise control: only your application servers, VPN egress, or MTA fleet can authenticate to the relay.
How should we handle authentication credentials in apps?
Store SMTP credentials in a secrets manager, rotate them when staff change, and never commit them to source control. Prefer per-environment credentials.
Does opening a new SMTP connection for every email hurt deliverability?
Excessive connect churn can add latency and load. Where your stack allows, reuse connections responsibly and follow documented rate and concurrency guidance.
Can legacy CRMs and printers use the same SMTP relay?
Often yes. SMTP is the common denominator for older systems; you can segment those streams with domains, headers, or subaccounts where your plan supports it.
What about message size and attachment limits?
Large payloads increase failure risk and processing time. Check your plan limits and consider hosting files externally with links in email when attachments are heavy.
Ready to move to reliable email infrastructure?
Start free with no card, or talk to sales for high-volume and enterprise.
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