EU SMTP relay for transactional email
Move existing app email to an EU-operated SMTP relay without rewriting your sending code. Configure your sender domain, swap SMTP host and credentials, and keep delivery logs, bounces, complaints, and webhooks in Postscale.
SMTP settings
smtp.postscale.io:587
port: 587
encryption: STARTTLS
When to use SMTP relay instead of REST API
SMTP is best when the sending code already exists. REST is best when your application owns the send flow and can call an HTTP API directly.
Existing apps
Frameworks, CMSs, and legacy systems usually expose SMTP host, username, password, and port settings already.
Minimal code changes
Swap credentials first, keep the old provider available for rollback, then move REST sends later if needed.
Same event pipeline
SMTP-originated messages still produce delivery, bounce, deferred, and complaint events through Postscale webhooks.
Migration checklist
Move SMTP traffic deliberately
Keep the old provider live while you verify sender authentication, send seed tests, and ramp production traffic.
Framework and CMS examples
Any stack that can send mail through SMTP can use Postscale as the relay while keeping the same delivery logs and webhook events.
Rails
Configure SMTP host, port, username, password, and sender domain.
Django
Configure SMTP host, port, username, password, and sender domain.
Laravel
Configure SMTP host, port, username, password, and sender domain.
WordPress
Configure SMTP host, port, username, password, and sender domain.
Node.js
Configure SMTP host, port, username, password, and sender domain.
PHP
Configure SMTP host, port, username, password, and sender domain.
EU/EEA-hosted primary service data
Postscale is built for teams evaluating an EU transactional email provider and a practical SMTP relay migration path.
EU transactional email providerTransactional Email API
Use REST for new sends and SMTP for legacy integrations. Both paths live in the same Postscale account.
View product pageSMTP relay docs
Use the docs for ports, credentials, TLS settings, SMTP headers, tags, metadata, and troubleshooting.
Read SMTP docsFrequently asked questions
Is SMTP slower than REST?
SMTP adds protocol negotiation, so REST is often simpler for new application code. SMTP is still the right migration path when an existing app, framework, CMS, or legacy system already sends mail through SMTP.
Can I use SMTP and REST on the same domain?
Yes. You can send through SMTP relay and REST API on the same verified sender domain while using the same Postscale delivery logs, suppressions, and webhook pipeline.
Does SMTP support webhooks?
Yes. SMTP-originated messages still produce delivery, bounce, deferred, and complaint events through Postscale webhooks.
How do I migrate from SendGrid, Mailgun, Postmark, or Amazon SES SMTP?
Create Postscale SMTP credentials, publish authentication records, swap host and credentials in the old integration, send test messages, then ramp production traffic gradually.
Move SMTP first, modernize later.
Keep legacy SMTP integrations working while Postscale handles sender authentication, delivery logs, and webhook events.