Paubox Email API

HIPAA compliant email API

Send secure, transactional emails that engage and improve the patient experience

A person in button up shirt facing away from the camera over shoulder viewing Paubox on screen in office environment

4,000+ customers trust Paubox to secure 68 million emails every month

The Queen's Health Systems logo in grayscale
Summit Health logo in grayscale
Walgreens logo
Curative logo in grayscale
AdaptHealth logo in grayscale

Get your apps to market faster

Start sending email notifications, reminders and updates without reinventing the wheel.

  • Drive innovation without worrying about HIPAA compliance
  • Reduce lengthy development timelines
  • Improve and optimize message deliverability
  • Track results on the Paubox analytics dashboard or utilize webhooks to pull event data into a third-party dashboard
View of a tablet with a product management roadmap on it.
Stylized screenshot depicting API Engage

Engage patients and others

Trigger transactional emails to create engaging experiences for patients and app users.

  • Easily customize and update messages with dynamic email templates
  • Add attachments and embedded images to deliver exceptional emails 
  • Personalize emails to send relevant content at the right time

Securely deliver messages

Send secure, HIPAA compliant transactional emails.

  • Include PHI and protected information
  • Emails are delivered with TLS 1.2 or higher
  • HIPAA compliant solution and HITRUST CSF certified
Over the shoulder view of a woman using a smartphone.
Stylized screenshot depicting API Setup

Set up quickly

Integrate quickly to get transactional emails up and running.

  • RESTful API and SMTP options available
  • Supports ten programming languages, including Javascript (via Node.js), Ruby, PHP, Python and others
  • In-depth developer docs for easy set up

How many emails do you send per month?



Billed annually
1-300 emails


Programmatically send HIPAA compliant email

Customizable API with multiple client libraries.

Optimized email deliverability

Maximizes email deliverability and avoids outbound email ending in spam folders by updating your SPF record and configuring DKIM and DMARC protocols.

Dynamic email templates

Create templated messages that can be customized with dynamic data.


HITRUST CSF certified

Our solutions have met key regulatory requirements, industry defined requirements, and appropriately manage risk.


TLS protocols 1.2 & 1.3

As per NSA guidance, Paubox supports only TLS 1.2 and TLS 1.3. The following obsolete protocols are not supported: SSL 2.0, SSL 3.0, TLS 1.0, and TLS 1.1.

Blanket TLS email encryption

Maximize the security of your organization’s emails by enforcing TLS secure email for every email sent and every campaign. No cumbersome portal login required for recipients. Blanket TLS email encryption is our unique, patented solution.

Two-factor authentication

Require authentication beyond a username and password when logging into your Paubox account.

U.S. data centers

Rely on our cloud-based, redundant infrastructure with 99.99%, uptime. Customer data is stored encrypted at-rest and solely in U.S data centers.


Real-time analytics

Comprehensive email analytics, mail logs, ruleset access, and quarantine.


Webhooks alert you when a message has been delivered, has a temporary failure, or has a permanent failure.



Use our RESTful APIs that are built on HTTPS and return JSON for clear implementation.


Deliver your email via our servers instead of your own client or server.

Comprehensive client libraries

Code in your preferred language with open source libraries and use cases in Node.JS, Ruby, Python, PHP, Ruby on Rails, Java, Perl, and C#.

API docs

Expedite end-to-end integration time with our robust API documentation.


Help center

Learn how to use Paubox products quickly with concise how-to articles, and step-by-step instructions.

Phone support

Our customer success team is available by phone for extended hours, Monday through Friday, to assist with any technical or support issue our customers might have.

Testimonial headshot

Daniel Nelson, CTO, PlateJoy

When I learned about Paubox, I knew it was exactly what I needed. There wasn’t really even a question. For the vast majority of users, the experience would just be email—familiar, ubiquitous email.

Daniel Nelson

Why Paubox?

Paubox Icons - 31

Drive app usage for a better patient experience

Deliver personalized notifications and reminders that engage patients and other users.

Blue Open Folder with Unsecured lock and Exclamation mark icon

Focus on your product

You build. Let us maintain the HIPAA compliant email infrastructure.

Blue iMac Virus Warning icon with bug on screen and warning symbol

Reduce risk

Every email sent is HIPAA compliant, every time. Paubox Email API is HITRUST CSF certified and offers a business associate agreement for all customers.

Blue Helpdesk Support icon, person wearing headset with now typing speech bubble

Get help when you need it

Paubox customer service is a best-in-class, U.S.-based team who are available via email or phone.

How Paubox Email API works

Blue Emails sent icon


Email sent via your app

Your application triggers an email to be sent with Paubox Email API

Blue Encrypted Mail icon


Emails get encrypted

Emails are seamlessly encrypted by Paubox servers with 128/256-bit AES encryption

Protection checkmark shield icon


Protect emails in transit

Emails are protected while on their way to the recipient’s inbox with TLS 1.2 encryption protocol and higher

Secure email icon


No TLS 1.2+? No problem!

If the destination inbox can’t receive encrypted email, then a secure link is delivered to view the message

Integrate in minutes

Deliver secure email faster with our REST APIs and SMTP libraries

  • SDKs for 10 programming languages
  • Detailed developer documentation available
  • Test out the API with up to 300 emails/mo free
// Send secure email using the Paubox JavaScript/Node.js Library
"use strict";
const pbMail = require('paubox-node');
const service = pbMail.emailService();

var options = {
  from: '[email protected]',
  to: ['[email protected]'],
  subject: 'Testing!',
  text_content: 'Hello World!',
  html_content: '<html><head></head><body><h1>Hello World!</h1></body></html>',

var message = pbMail.message(options)

.then(response => {
  console.log("Send Message method Response: " + JSON.stringify(response));
}).catch(error => {
  console.log("Error in Send Message method: " + JSON.stringify(error));

# Send secure email using the Paubox Ruby Library
require 'Paubox'
require 'json'
require 'mail'

message = do
  from            '[email protected]'
  to              '[email protected]'
  cc              '[email protected]'
  subject         'HIPAA-compliant email made easy'

  text_part do
    body          'This message will be sent securely by Paubox.'

  html_part do
    content_type  'text/html; charset=UTF-8'
    body          '<h1>This message will be sent securely by Paubox.</h1>'

  delivery_method Mail::Paubox

=> {"message"=>"Service OK", "sourceTrackingId"=>"2a3c048485aa4cf6"}

=> "2a3c048485aa4cf6"
# Send secure email using the Paubox Ruby on Rails Extended Gem
class UserMailer < ApplicationMailer
  def welcome_email
    @user = params[:user]
    @url  = user_url(@user)
    delivery_options = { allow_non_tls: true }
         subject: "Welcome!",
         delivery_method_options: delivery_options)
# Send secure email using the Paubox Python 3 Library
import paubox
from paubox.helpers.mail import Mail

from config import Config 
with open("config.cfg") as config_file:
    paubox_config = Config(config_file)

paubox_client = paubox.PauboxApiClient(paubox_config.PAUBOX_API_KEY, 
recipients = ["[email protected]"]
from_ = "[email protected]"
subject = "Testing!"
content = {"text/plain": "Hello World!"}
mail = Mail(from_, subject, recipients, content)
response = paubox_client.send(mail.get())
// Send secure email using the Paubox C# Library
static SendMessageResponse SendMessage()
  Message message = new Message();
  Content content = new Content();
  Header header = new Header();
  message.Recipients = new string[] { "[email protected]",
  "[email protected]" };
  header.From = "[email protected]";
  message.Cc = new string[] { "[email protected]" };
  message.Bcc = new string[] { "[email protected]" };
  header.Subject = "Testing!";
  header.ReplyTo = "[email protected]";
  content.PlainText = "Hello World!";
  message.Header = header;
  message.Content = content;
  SendMessageResponse response = EmailLibrary.SendMessage(message);
  return response;
static SendMessageResponse SendMessage()
  Message message = new Message();
  Content content = new Content();
  Header header = new Header();
  message.setRecipients(new String[] { "[email protected]",
  "[email protected]" });
  header.setFrom("[email protected]");
  message.setCc(new String[] { "[email protected]" });
  message.setBcc(new String[] { "[email protected]" });
  header.setReplyTo("[email protected]");
  content.setPlainText("Hello World!");

  EmailInterface email = new EmailService();
  SendMessageResponse response = email.SendMessage(message);
  return response;
// Send secure email using the Paubox PHP Library
require_once __DIR__ . '/vendor/autoload.php';

$dotenv = Dotenv\Dotenv::create(__DIR__);

$paubox = new Paubox\Paubox();

$message = new Paubox\Mail\Message();
$content = new Paubox\Mail\Content();
$content->setPlainText("Hello World");

$header = new Paubox\Mail\Header();
$header->setFrom("[email protected]");

$recipients = array();
array_push($recipients,'[email protected]');


$sendMessageResponse = new Paubox\Mail\SendMessageResponse();
$sendMessageResponse = $paubox->sendMessage($message);
# Send secure email using the Paubox Perl Library
use strict;
use warnings;
use Paubox_Email_SDK;

my $messageObj = new Paubox_Email_SDK::Message(
   'from' => '[email protected]',   
   'to' => ['[email protected]'],
   'subject' => 'Testing!',
   'text_content' => 'Hello World!',
   'html_content' => '<html><body><h1>Hello World!</h1></body></html>'  

my $service = Paubox_Email_SDK -> new();
my $response = $service -> sendMessage($messageObj);
print $response;

Developer resources

Download software development kits and review instructions in the developer document portal.

Related resources

A person using a computer with document overlays on the image.

Developer Resources

Paubox Email API documentation hub

Learn how to send HIPAA compliant email with confidence and integrate TLS 1.3 encrypted email in minutes with our email API.

Read more

API connection graphic

Blog Post

Why healthcare businesses choose Paubox Email API

Paubox Email API is a great option for covered entities to send transactional emails at scale by quickly integrating our secure, HIPAA compliant solution into their applications.

Read more

Abstract graphic showing characters and elements interacting with an API

Blog Post

Dynamic email templates have been added to Paubox Email API

Dynamic email templates have been added to Paubox Email API.  This new feature is included for all existing and future Paubox Email API customers.

Read more

Start encrypting emails