SMTP

Nodemailer

Nodemailer is not deprecated. Create a transport with createTransport, point it at smtp.unitpost.com on port 587 (STARTTLS) or 465 (implicit TLS), and send from a verified domain. Port 25 is blocked on most clouds — don't use it. The same transport works in Express, Next.js, and NestJS.

1. 1

   Install Nodemailer

   Add it to your Node.js project (Node 18+). The package is actively maintained.

   Shell

   npm install nodemailer

2. 2

   Create a transport

   Point createTransport at smtp.unitpost.com. Use port 587 with secure: false for STARTTLS, or port 465 with secure: true for implicit TLS. The username is always unitpost; the password is your API key with emails:send.

   JavaScript

   import nodemailer from "nodemailer";
   
   const transporter = nodemailer.createTransport({
     host: "smtp.unitpost.com",
     port: 587,
     secure: false,
     requireTLS: true,
     auth: {
       user: "unitpost",
       pass: process.env.UNITPOST_API_KEY,
     },
   });

   Port 25 vs 587: 25 is the legacy submission port and is blocked by AWS, GCP, and most VPS providers. 587 with STARTTLS is what you want. 465 is implicit TLS if 587 is filtered.

3. 3

   Send an email

   The from address must be on a domain you've verified in Unitpost. This is the same sendMail call in a Next.js Route Handler or a NestJS provider.

   JavaScript

   await transporter.sendMail({
     from: "you@yourdomain.com",
     to: "customer@example.com",
     subject: "Hello from Unitpost",
     html: "<h1>Welcome!</h1><p>Sent via SMTP.</p>",
   });

4. 4

   Verify it in the dashboard

   Open Activity in your Unitpost dashboard — the message appears alongside API sends, with delivery, open, and click status. Framework-specific walkthroughs: Next.js, NestJS, Express.

Supabase

Point Supabase's custom SMTP at Unitpost so auth emails send from your own verified domain — and skip Supabase's built-in auth-email rate limits.

1. 1

   Open Supabase SMTP settings

   In the Supabase dashboard go to Project Settings → Authentication → SMTP Settings and enable Custom SMTP.

2. 2

   Enter your Unitpost credentials

   Host	smtp.unitpost.com
   Port	587
   Username	unitpost
   Password	Your Unitpost API key
   Sender email	auth@yourdomain.com (verified)
   Sender name	Your app name

   The sender email must be on a domain you've verified in Unitpost, or sends are rejected with a 550.

3. 3

   Save and send a test

   Save the settings, then trigger a magic link or signup confirmation. Supabase renders its own auth templates; Unitpost just delivers them.

4. 4

   Confirm delivery

   The auth email shows up in your Unitpost Activity view with full tracking.

Because delivery now runs through Unitpost, your plan's sending limits apply instead of Supabase's default auth-email throttle.

WordPress

WordPress sends mail via PHP's `mail()` by default, which most hosts deliver poorly. Route it through Unitpost SMTP with a plugin like WP Mail SMTP.

1. 1

   Install an SMTP plugin

   From Plugins → Add New, install and activate WP Mail SMTP (or a comparable SMTP plugin).

2. 2

   Choose the "Other SMTP" mailer

   In the plugin settings, pick the generic Other SMTP option (not a named provider).

3. 3

   Enter your Unitpost SMTP settings

   SMTP Host	smtp.unitpost.com
   Encryption	TLS (STARTTLS)
   SMTP Port	587
   Authentication	On
   SMTP Username	unitpost
   SMTP Password	Your Unitpost API key
   From Email	you@yourdomain.com (verified)

   Store the API key in the plugin's password field. Set the From Email to an address on your verified domain.

4. 4

   Send a test email

   Use the plugin's Email Test tab to send yourself a message, then confirm it in your Unitpost Activity view.

Auth0

Configure a custom SMTP email provider in Auth0 so your tenant's emails deliver from your verified domain through Unitpost.

1. 1

   Open the email provider settings

   In the Auth0 dashboard go to Branding → Email Provider (or Emails → Provider on older tenants) and choose SMTP.

2. 2

   Enter your Unitpost credentials

   From	you@yourdomain.com (verified)
   Host	smtp.unitpost.com
   Port	587
   Username	unitpost
   Password	Your Unitpost API key

3. 3

   Save and send a test

   Save the provider, then use Auth0's Send Test Email button to verify the connection.

4. 4

   Enable the emails you want

   Under Branding → Email Templates, toggle on verification, welcome, password-reset, and other templates. Auth0 renders them; Unitpost delivers.

Rails

Set Action Mailer's SMTP settings to route your Rails app's mail through Unitpost. Same job as Nodemailer — different stack.

1. 1

   Configure Action Mailer

   In your environment config (e.g. config/environments/production.rb), set the delivery method and SMTP settings.

   Ruby

   config.action_mailer.delivery_method = :smtp
   config.action_mailer.smtp_settings = {
     address:              "smtp.unitpost.com",
     port:                 587,
     user_name:            "unitpost",
     password:             ENV["UNITPOST_API_KEY"],
     authentication:       :plain,
     enable_starttls_auto: true,
   }

2. 2

   Set your sender

   Use a from address on a verified domain in your mailer.

   Ruby

   class UserMailer < ApplicationMailer
     default from: "you@yourdomain.com"
   
     def welcome_email
       mail(to: "customer@example.com", subject: "Welcome!")
     end
   end

3. 3

   Deliver and verify

   Trigger the mailer (UserMailer.welcome_email.deliver_now) and confirm the send in your Unitpost Activity view.

Laravel

Laravel reads SMTP settings from your `.env`. Point the mailer at Unitpost and send from a verified domain.

1. 1

   Set your mail environment variables

   Add the following to your .env file.

   Shell

   MAIL_MAILER=smtp
   MAIL_HOST=smtp.unitpost.com
   MAIL_PORT=587
   MAIL_USERNAME=unitpost
   MAIL_PASSWORD=${UNITPOST_API_KEY}
   MAIL_ENCRYPTION=tls
   MAIL_FROM_ADDRESS=you@yourdomain.com
   MAIL_FROM_NAME="${APP_NAME}"

   MAIL_FROM_ADDRESS must be on a domain you've verified in Unitpost.

2. 2

   Clear the config cache

   If you cache config in production, refresh it so the new values load.

   Shell

   php artisan config:clear

3. 3

   Send and verify

   Send a mailable (e.g. Mail::to($user)->send(new WelcomeMail())) and confirm it in your Unitpost Activity view.

Django

Configure Django's built-in SMTP email backend to send through Unitpost. This is the same job as Nodemailer — Python instead of Node.

1. 1

   Configure your settings

   Add the SMTP settings to settings.py. Keep the API key in an environment variable.

   Python

   EMAIL_BACKEND = "django.core.mail.backends.smtp.EmailBackend"
   EMAIL_HOST = "smtp.unitpost.com"
   EMAIL_PORT = 587
   EMAIL_USE_TLS = True
   EMAIL_HOST_USER = "unitpost"
   EMAIL_HOST_PASSWORD = os.environ["UNITPOST_API_KEY"]
   DEFAULT_FROM_EMAIL = "you@yourdomain.com"

2. 2

   Send an email

   Use send_mail or an EmailMessage. The from address must be on a verified domain.

   Python

   from django.core.mail import send_mail
   
   send_mail(
       subject="Hello from Unitpost",
       message="Sent via SMTP.",
       from_email="you@yourdomain.com",
       recipient_list=["customer@example.com"],
       html_message="<h1>Welcome!</h1>",
   )

3. 3

   Verify delivery

   Check your Unitpost Activity view for the message and its status.

PHPMailer

Use PHPMailer's SMTP mode to deliver through Unitpost from plain PHP. Port 587 with STARTTLS; don't use port 25.

1. 1

   Install PHPMailer

   Add it via Composer.

   Shell

   composer require phpmailer/phpmailer

2. 2

   Configure and send

   Set PHPMailer to SMTP mode with your Unitpost credentials.

   PHP

   <?php
   use PHPMailer\PHPMailer\PHPMailer;
   
   $mail = new PHPMailer(true);
   $mail->isSMTP();
   $mail->Host       = "smtp.unitpost.com";
   $mail->SMTPAuth   = true;
   $mail->Username   = "unitpost";
   $mail->Password   = getenv("UNITPOST_API_KEY");
   $mail->SMTPSecure = PHPMailer::ENCRYPTION_STARTTLS;
   $mail->Port       = 587;
   
   $mail->setFrom("you@yourdomain.com", "Your App");
   $mail->addAddress("customer@example.com");
   $mail->isHTML(true);
   $mail->Subject = "Hello from Unitpost";
   $mail->Body    = "<h1>Welcome!</h1><p>Sent via SMTP.</p>";
   $mail->send();

3. 3

   Verify delivery

   The message appears in your Unitpost Activity view with full tracking.

Next.js

Send from a Next.js Route Handler with Nodemailer pointed at Unitpost SMTP. Keep the API key on the server — never in a Client Component.

1. 1

   Install Nodemailer

   Shell

   npm install nodemailer
   npm install -D @types/nodemailer

2. 2

   Create a Route Handler

   Server-only. The from address must be on a verified domain.

   TypeScript

   import nodemailer from "nodemailer";
   import { NextResponse } from "next/server";
   
   const transporter = nodemailer.createTransport({
     host: "smtp.unitpost.com",
     port: 587,
     secure: false,
     requireTLS: true,
     auth: {
       user: "unitpost",
       pass: process.env.UNITPOST_API_KEY,
     },
   });
   
   export async function POST() {
     await transporter.sendMail({
       from: "you@yourdomain.com",
       to: "customer@example.com",
       subject: "Hello from Next.js",
       html: "<p>Sent via SMTP.</p>",
     });
     return NextResponse.json({ ok: true });
   }

3. 3

   Verify delivery

   Check Activity. Same transport as the Nodemailer guide — this page is the Next.js wiring.

NestJS

Inject a Nodemailer transport in NestJS and send over Unitpost SMTP. Same credentials as any other stack.

1. 1

   Install Nodemailer

   Shell

   npm install nodemailer
   npm install -D @types/nodemailer

2. 2

   Provide a transporter

   TypeScript

   import { Injectable } from "@nestjs/common";
   import nodemailer from "nodemailer";
   
   @Injectable()
   export class MailService {
     private transporter = nodemailer.createTransport({
       host: "smtp.unitpost.com",
       port: 587,
       secure: false,
       auth: {
         user: "unitpost",
         pass: process.env.UNITPOST_API_KEY,
       },
     });
   
     sendWelcome(to: string) {
       return this.transporter.sendMail({
         from: "you@yourdomain.com",
         to,
         subject: "Welcome",
         html: "<p>Sent via SMTP.</p>",
       });
     }
   }

3. 3

   Verify delivery

   The send shows up in Activity. See also Nodemailer.

Express

Send from an Express route with Nodemailer pointed at Unitpost. Keep the key in env, not in the repo.

1. 1

   Install Nodemailer

   Shell

   npm install nodemailer

2. 2

   Send from a route

   JavaScript

   import express from "express";
   import nodemailer from "nodemailer";
   
   const transporter = nodemailer.createTransport({
     host: "smtp.unitpost.com",
     port: 587,
     secure: false,
     requireTLS: true,
     auth: {
       user: "unitpost",
       pass: process.env.UNITPOST_API_KEY,
     },
   });
   
   const app = express();
   app.post("/send", async (_req, res) => {
     await transporter.sendMail({
       from: "you@yourdomain.com",
       to: "customer@example.com",
       subject: "Hello from Express",
       html: "<p>Sent via SMTP.</p>",
     });
     res.json({ ok: true });
   });

3. 3

   Verify delivery

   Confirm in Activity.

Python

Python's smtplib talks SMTP directly. Point it at Unitpost on port 587 with STARTTLS. Django and Flask wrap this; this page is the bare client.

1. 1

   Send with smtplib

   Python

   import os
   import smtplib
   from email.message import EmailMessage
   
   msg = EmailMessage()
   msg["From"] = "you@yourdomain.com"
   msg["To"] = "customer@example.com"
   msg["Subject"] = "Hello from Python"
   msg.set_content("Sent via SMTP.")
   msg.add_alternative("<p>Sent via SMTP.</p>", subtype="html")
   
   with smtplib.SMTP("smtp.unitpost.com", 587) as smtp:
       smtp.starttls()
       smtp.login("unitpost", os.environ["UNITPOST_API_KEY"])
       smtp.send_message(msg)

2. 2

   Framework wrappers

   Using a framework? Django, Flask, FastAPI.

Flask

Configure Flask-Mail's SMTP settings for Unitpost and send from a verified domain.

1. 1

   Install Flask-Mail

   Shell

   pip install Flask-Mail

2. 2

   Configure and send

   Python

   import os
   from flask import Flask
   from flask_mail import Mail, Message
   
   app = Flask(__name__)
   app.config.update(
       MAIL_SERVER="smtp.unitpost.com",
       MAIL_PORT=587,
       MAIL_USE_TLS=True,
       MAIL_USERNAME="unitpost",
       MAIL_PASSWORD=os.environ["UNITPOST_API_KEY"],
       MAIL_DEFAULT_SENDER="you@yourdomain.com",
   )
   mail = Mail(app)
   
   def send_welcome(to: str) -> None:
       msg = Message("Welcome", recipients=[to], html="<p>Sent via SMTP.</p>")
       mail.send(msg)

3. 3

   Verify delivery

   Check Activity. Bare Python: smtplib.

FastAPI

Call Python's SMTP client from a FastAPI route. Same host, username, and API-key password as every other stack.

1. 1

   Send from a route

   Python

   import os
   import smtplib
   from email.message import EmailMessage
   from fastapi import FastAPI
   
   app = FastAPI()
   
   @app.post("/send")
   def send() -> dict[str, bool]:
       msg = EmailMessage()
       msg["From"] = "you@yourdomain.com"
       msg["To"] = "customer@example.com"
       msg["Subject"] = "Hello from FastAPI"
       msg.set_content("Sent via SMTP.")
       with smtplib.SMTP("smtp.unitpost.com", 587) as smtp:
           smtp.starttls()
           smtp.login("unitpost", os.environ["UNITPOST_API_KEY"])
           smtp.send_message(msg)
       return {"ok": True}

2. 2

   Verify delivery

   Confirm in Activity.

Go

Go's net/smtp client can STARTTLS to Unitpost on port 587. Username is the literal `unitpost`; password is an API key.

1. 1

   Send with net/smtp

   Go

   package main
   
   import (
       "crypto/tls"
       "net/smtp"
       "os"
   )
   
   func main() {
       host := "smtp.unitpost.com"
       auth := smtp.PlainAuth("", "unitpost", os.Getenv("UNITPOST_API_KEY"), host)
       to := []string{"customer@example.com"}
       msg := []byte("From: you@yourdomain.com\r\n" +
           "To: customer@example.com\r\n" +
           "Subject: Hello from Go\r\n" +
           "\r\n" +
           "Sent via SMTP.\r\n")
   
       c, err := smtp.Dial(host + ":587")
       if err != nil {
           panic(err)
       }
       defer c.Close()
       if err = c.StartTLS(&tls.Config{ServerName: host}); err != nil {
           panic(err)
       }
       if err = c.Auth(auth); err != nil {
           panic(err)
       }
       if err = c.Mail("you@yourdomain.com"); err != nil {
           panic(err)
       }
       if err = c.Rcpt(to[0]); err != nil {
           panic(err)
       }
       w, err := c.Data()
       if err != nil {
           panic(err)
       }
       if _, err = w.Write(msg); err != nil {
           panic(err)
       }
       if err = w.Close(); err != nil {
           panic(err)
       }
       _ = c.Quit()
   }

   Port 587 needs an explicit STARTTLS before AUTH (PLAIN and LOGIN are both accepted). From must be on a verified domain.

2. 2

   Verify delivery

   The message appears in Activity.

Spring Boot

Set Spring Mail properties to Unitpost SMTP and send with JavaMailSender. Port 587, STARTTLS, username `unitpost`.

1. 1

   Set mail properties

   Properties

   spring.mail.host=smtp.unitpost.com
   spring.mail.port=587
   spring.mail.username=unitpost
   spring.mail.password=${UNITPOST_API_KEY}
   spring.mail.properties.mail.smtp.auth=true
   spring.mail.properties.mail.smtp.starttls.enable=true

2. 2

   Send with JavaMailSender

   Java

   MimeMessage message = mailSender.createMimeMessage();
   MimeMessageHelper helper = new MimeMessageHelper(message, true);
   helper.setFrom("you@yourdomain.com");
   helper.setTo("customer@example.com");
   helper.setSubject("Hello from Spring");
   helper.setText("<p>Sent via SMTP.</p>", true);
   mailSender.send(message);

3. 3

   Verify delivery

   Check Activity.

.NET

System.Net.Mail.SmtpClient is obsolete. Use MailKit, STARTTLS on 587, username `unitpost`, API key as password.

1. 1

   Add MailKit

   Shell

   dotnet add package MailKit

2. 2

   Send

   C#

   using MailKit.Net.Smtp;
   using MailKit.Security;
   using MimeKit;
   
   var message = new MimeMessage();
   message.From.Add(MailboxAddress.Parse("you@yourdomain.com"));
   message.To.Add(MailboxAddress.Parse("customer@example.com"));
   message.Subject = "Hello from .NET";
   message.Body = new TextPart("html") { Text = "<p>Sent via SMTP.</p>" };
   
   using var client = new SmtpClient();
   await client.ConnectAsync("smtp.unitpost.com", 587, SecureSocketOptions.StartTls);
   await client.AuthenticateAsync("unitpost", Environment.GetEnvironmentVariable("UNITPOST_API_KEY"));
   await client.SendAsync(message);
   await client.DisconnectAsync(true);

3. 3

   Verify delivery

   Confirm in Activity.