Overview
What SMTP is
SMTP is the standard protocol for sending email through a mail server, so you can connect almost any mail service or self-hosted server that speaks it.
Courier sits in front of it as one API, a visual editor, journeys, and every other channel, so you keep SMTP for delivery and build multi-channel notifications on top.
You need a Courier account and your own SMTP server details: host, port, username, and password.
Why Courier
What you get with SMTP + Courier
Design beautiful emails, no code
Build and edit email in Courier's visual editor. Product and marketing change content and layout without shipping code, then send through your SMTP server.
Automate multi-step journeys
Onboarding, drip, and lifecycle sequences with delays and branching, all delivered through your SMTP connection.
Add SMS, push, and chat
The same notification can reach every channel. Add one when you need it, no new integration in your code.
Add an in-app inbox
A new, easy add-on: drop Courier Inbox into your web or mobile app so users get an in-product notification center alongside email.
Localize a template in seconds
Pick a language and let Courier translate the whole template with AI, then tweak any string. One template, every market.
Send to lists and audiences
Broadcast a one-off or recurring message to an entire list through SMTP, alongside your transactional email.
Use cases
What teams build with it
Setup
Connect it in minutes
An admin adds SMTP once on the Integrations page in Courier. Once connected, anyone on your team can design and send email through your SMTP server, and add channels whenever they need them.
FAQ
Frequently asked questions
Can I use SMTP with Courier?
Yes. Courier connects to any standard SMTP email server, so you can send transactional email through your own mail server using Courier's Send API and Design Studio, without writing raw SMTP code.
Do I need my own SMTP server?
Yes. Courier is not an SMTP server itself; it relays messages through the SMTP host you provide. You bring the server, hostname, and login, and Courier handles content, routing, and other channels on top.
What do I need to connect SMTP to Courier?
Your SMTP host, port, username, password, and a From Address. Enter them in Courier's SMTP provider settings and click Save. Port 587 or 465 are typical for secure submission.
What TLS settings does Courier support for SMTP?
Courier always uses TLS. For port 587 it sets requireTLS: true for STARTTLS; for port 465 it sets secure: true for implicit TLS. Pick the port your server expects for encrypted submission.
Can I use different SMTP credentials per message?
Yes. Override the transport per send with message.providers.smtp.override.config, so one Courier workspace can route individual messages through different SMTP servers or credentials. Attachments can also be passed through message overrides.
Does Courier send from fixed IP addresses?
No. Courier connects to your SMTP server from AWS-hosted infrastructure and does not use fixed outbound IPs. If your server allowlists by IP, coordinate with Amazon's published AWS IP ranges rather than a static Courier address.
Is Courier a replacement for my SMTP server?
No. Courier is not itself an SMTP server; your mail server still delivers the email. Courier sits in front, adding the Send API, Journeys, and Design Studio, plus SMS, push, and Courier Inbox on one API.
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