Standard SMTP compatibility
Connect applications, websites, CRM tools, and legacy systems that already support standard SMTP.
Hosted Cloud SMTP Relay Service
Reliable SMTP Relay Service for Business Email
Route transactional and bulk email from applications, websites, and existing systems through uSpeedo. Connect with standard authenticated SMTP, scale outbound sending, and monitor delivery performance without operating your own mail infrastructure.
Core capabilities
- Standard SMTP integration
- Authenticated outbound sending
- Delivery and bounce visibility
Connect existing systems and manage email delivery performance from one platform.
A hosted SMTP mail relay service for existing systems
An SMTP relay service accepts outbound email from your application or mail system and routes it to recipient mail servers. It separates business applications from the work of operating delivery infrastructure, making it easier to scale sending and monitor results.
uSpeedo works as a cloud SMTP relay service for transactional and bulk email. Configure your existing system with the SMTP endpoint and authenticated credentials, then use delivery and bounce signals to understand what happens after each send.
Reliable outbound SMTP relay
Everything you need from an SMTP relay service provider
Connect established systems to a hosted bulk SMTP relay service without rewriting the application around a new API.
Authenticated relay access
Use assigned SMTP credentials to control access and prevent unauthorized use of your sending account.
Hosted cloud infrastructure
Route outbound email through managed infrastructure instead of maintaining a self-hosted SMTP server.
Transactional and bulk sending
Support account notifications, receipts, alerts, lifecycle messages, and permission-based bulk campaigns.
Delivery event visibility
Track delivery status, bounces, and engagement events to diagnose issues and improve sending operations.
Deliverability support
Combine domain authentication, reputation safeguards, and delivery monitoring to support inbox placement.
Where an outbound SMTP relay service fits
Add managed delivery to software that already generates email.
Business applications
Relay account alerts, reports, workflow updates, and system-generated notifications.
E-commerce platforms
Send confirmations, receipts, shipping updates, and permission-based promotional email.
CRM and marketing tools
Connect tools that support custom SMTP credentials to a scalable sending service.
Legacy systems
Modernize outbound delivery while keeping systems that cannot easily adopt a new REST API.
Connect to uSpeedo SMTP relay
Move outbound email to a hosted SMTP relay service with a straightforward configuration flow.
- 01
Set up your sender
Create the sending identity and complete the required domain authentication configuration.
- 02
Get SMTP credentials
Obtain the SMTP endpoint and authenticated account credentials for your environment.
- 03
Configure your system
Enter the endpoint and credentials in your application, website, or existing email software.
- 04
Test and monitor
Send a controlled test, then review delivery status and bounce feedback before scaling volume.
SMTP relay vs. Email API
Both methods use uSpeedo delivery infrastructure. Choose based on how your system is built and how much programmatic control you need.
Best fit
- SMTP Relay
- Existing systems and software with SMTP support
- Email API
- Modern products and event-driven workflows
Integration
- SMTP Relay
- Configure an SMTP endpoint and credentials
- Email API
- Call REST endpoints from application code
Migration effort
- SMTP Relay
- Usually minimal when SMTP is already supported
- Email API
- Requires development work but offers deeper control
Delivery feedback
- SMTP Relay
- Monitor sending results in uSpeedo
- Email API
- Use API events in product workflows and monitoring
FAQ
Frequently asked questions
What is an SMTP relay service?+
An SMTP relay service receives outbound email from an authenticated application or system and routes it to recipient mail servers using managed delivery infrastructure.
Why use a cloud SMTP relay service instead of a self-hosted server?+
A hosted service reduces the operational work of maintaining mail infrastructure and provides a clearer path to scalable sending, delivery monitoring, bounce visibility, and reputation management.
Can I use SMTP relay for transactional and bulk email?+
Yes. uSpeedo SMTP relay can support automated transactional messages and permission-based bulk campaigns generated by compatible systems.
How do I choose the best SMTP relay service for my business?+
Compare SMTP compatibility, authenticated access, sending scale, delivery and bounce visibility, domain authentication support, and the provider’s ability to support your transactional or permission-based bulk email use case.
Is SMTP relay the same as an Email API?+
No. SMTP relay uses the standard SMTP protocol and is often faster to connect to existing software. An Email API uses programmable endpoints and offers deeper control for application workflows.
How does uSpeedo control SMTP relay access?+
SMTP connections use authenticated account credentials. Sender setup and domain authentication also help protect the sending identity and support responsible delivery.
Email API & SMTP Relay
Get startedMove outbound email to a reliable SMTP relay service
Connect your existing application or email system to uSpeedo and start testing authenticated SMTP delivery.
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