Fast and reliable Email Delivery Service

Get your emails delivered instantly

We get your emails delivered in seconds. Your customers never have to wait for the emails they are expecting or need immediately, like password resets, order confirmations etc.

We do all the hard work to place your emails straight in your recipient’s inbox, so you can focus on delighting even more customers and growing your business. logo
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High priority for your transactional emails

Transactional emails, such as password resets, email confirmation links, order receipts must be delivered immediately. We ensure that they are always our top priority.

That’s why we’ve separated our sending infrastructure, to ensure this priority. When you use a transactional sending account, you know your most important emails will never be affected even by the biggest of your email marketing campaigns.
A screenshot of a form used to add a new sending account.

Build your stellar sender reputation

Your sender reputation is critical for email delivery and should always be your concern. We work with you every step of the way to improve your sender reputation score and keep it at a high level.

Relations with industry movers and shakers

Coresender maintains good relations with all prominent organizations in the industry. This lets us better address your deliverability problems, gather insights regarding your sender reputation and look after your individual email campaigns.
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Email bounce management

Soft and hard bounces are important to email deliverability and influence your sender reputation. We monitor your bounce rate, provide detailed insights and help you identify the reason for the failed delivery.

Dedicated IP addresses

We keep dedicated IPs set aside for exclusive use by customers sending over 250,000 emails per month. For newly provisioned IP addresses we will apply an automatic warming-up plan, so you can reach your desired sending levels without any issues.

24/7 Monitoring

Coresender engineers and automated systems work round the clock to ensure all your emails get delivered. They step in the moment there are any issues that need our attention.

Email authentication

Authentication helps inbox providers separate legitimate emails from spam. We automatically add SPF and DKIM authentication headers to every email you send with a minimum configuration effort on your side. For additional anti-spoofing protection, we‘ll help you set up a DMARC policy.
require 'vendor/autoload.php';
use Coresender\Coresender;
use Coresender\Helpers\EmailBuilder;

$builder = new EmailBuilder();
   ->setFrom('', 'Jean-Luc Picard')
   ->addToRecipient('', 'Geordi La Forge')
   ->setSubject('I need engines')
   ->setBodyText('Geordi, I need engines, now!')
   ->setBodyHtml('<p>Geordi, I need engines, <strong>now!</strong></p>');

$sendingApi = Coresender::createSendEmailApi(
 '<<Coresender sending account id>>',
  '<<Coresender sending account API key>>'
import com.coresender.sdk.Coresender;
import java.util.List;

public class Example1 {
 public static void main(String[] args) {
   Coresender coresender = Coresender.builder()
        .accountId("<<Coresender sending account id>>")
        .apiKey("<<Coresender sending account API key>>")

       .from(Email.Address.of("", "Jean-Luc Picard"))
       .to(List.of(Email.Address.of("", "Geordi La Forge")))
       .subject("I need engines")
       .bodyText("Geordi, I need engines, now!")
.bodyHtml("<p>Geordi, I need engines, <strong>now!</strong></p>")
.listId("no list")
const {Coresender, BodyType} = require('coresender');

const client = new Coresender('<<Coresender sending account id>>',
   '<<Coresender sending account API key>>');

const params = {
   fromEmail: '',
   toEmail: '',
   subject: 'Hello Bob',
   body: '<div>Nice to meet you.</div>',
   bodyType: BodyType.HTML,

const result = await client.simpleEmail(params);
import asyncio
import uuid
import coresenderasync def main():
     sending_account_id='<<Coresender sending account id>>',
     sending_account_key='<<Coresender sending account id>>',
     # debug=True # if True, then show some logs on stderr, or use `CORESENDER_DEBUG` environment variable
 )  custom_id = str(uuid.uuid4())
 rsp = await rq.simple_email(
     subject='Coresender test ' + custom_id,
 print(rsp)if __name__ == '__main__':
curl -X POST \
  -u '<<Coresender sending account id>>:<<Coresender sending account API key>>' \
  -d $'[
      "from": {
        "email": "",
        "name": "Jean-Luc Picard"
      "to": [{
        "email": "",
        "name": "Geordi La Forge"
      "subject": "I need engines",
      "body": {
        "text": "Geordi, I need engines, now!"


Our official client libraries will get you integrated in minutes. We have covered all popular languages including PHP, Java, Node.js Python, cURL.
See source codes on GitHub
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SMTP service for quick and effortless integration

With our SMTP service, you can get your integration running in minutes. It is the easiest way to migrate from your in-house mailing server and resolve your most immediate performance or deliverability issues. Many online applications support SMTP out-of-the-box and switching to Coresender is just a matter of replacing some credentials.

See all SMTP integration guides
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 "event": "",
 "received_at": "2020-01-22T17:19:03.000648+00:00"
 "message_id": "861a063b-d9a2-407c-8b5d-a00874a169d0",
 "custom_id": "internal-123",
 "recipient_email": "",
 "from_email": "",
 "account_id": "d7585605-8346-41ea-a0d1-589e8e4f8632"
 "event": "message.hard_bounce",
 "received_at": "2020-01-22T17:19:03.000648+00:00"
 "message_id": "861a063b-d9a2-407c-8b5d-a00874a169d0",
 "custom_id": "internal-123",
 "recipient_email": "",
 "from_email": "",
 "account_id": "d7585605-8346-41ea-a0d1-589e8e4f8632"
 "event": "message.soft_bounce",
 "received_at": "2020-01-22T17:19:03.000648+00:00"
 "message_id": "861a063b-d9a2-407c-8b5d-a00874a169d0",
 "custom_id": "internal-123",
 "recipient_email": "",
 "from_email": "",
 "account_id": "d7585605-8346-41ea-a0d1-589e8e4f8632"
 "event": "",
 "received_at": "2020-01-22T17:46:01.000110+00:00"
 "message_id": "861a063b-d9a2-407c-8b5d-a00874a169d0",
 "custom_id": "internal-123",
 "recipient_email": "",
 "from_email": "",
 "account_id": "d7585605-8346-41ea-a0d1-589e8e4f8632",
 "user_agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_6) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/13.0.3 Safari/605.1.15"
 "event": "",
 "received_at": "2020-01-22T17:46:56.779110+00:00"
 "message_id": "861a063b-d9a2-407c-8b5d-a00874a169d0",
 "custom_id": "internal-123",
 "recipient_email": "",
 "from_email": "",
 "account_id": "d7585605-8346-41ea-a0d1-589e8e4f8632",
 "user_agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_6) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/13.0.3 Safari/605.1.15"
 "event": "message.unsubscribe",
 "received_at": "2020-01-22T17:46:56.779110+00:00"
 "message_id": "861a063b-d9a2-407c-8b5d-a00874a169d0",
 "custom_id": "internal-123",
 "recipient_email": "",
 "from_email": "",
 "account_id": "d7585605-8346-41ea-a0d1-589e8e4f8632",
 "list_id": "company_newsletters"
 "event": "message.spam_complaint",
 "received_at": "2020-01-22T17:46:56.779110+00:00"
 "message_id": "861a063b-d9a2-407c-8b5d-a00874a169d0",
 "custom_id": "internal-123",
 "recipient_email": "",
 "from_email": "",
 "account_id": "d7585605-8346-41ea-a0d1-589e8e4f8632"

Get notified about your messages with Webhooks

Webhooks can provide real-time updates on delivery and engagement. Your application can be notified about successful deliveries, bounces or spam complaints as well as message opens and tracking link clicks.

Explore useful statistics

We provide you with detailed insights into crucial data that will let you detect any possible issues and make sure your emails reach your clients. You’ll see how many emails were sent, how many were delivered, opened, clicked on. What the bounce rate was, which were marked spam and who unsubscribed.
A screenshot of summarized statistics.

Follow email-related activity events

Coresender tracks every single email for up to 60 days. You can search for a specific message and learn about its status. Handling delivery issues reported by your customers suddenly becomes very easy.
A screenshot of the activity list.

Messages timelines

Every email you send has its own timeline with sequential event data, and you have access to the history of events like delivery, opens, clicks etc. for up to 60 days.
A screenshot of a message timeline.

Use separate sending accounts

You can use separate sending accounts according to your needs. It’s best to use one account to send transactional emails and a different one for marketing campaigns. It’s even a good idea to use different accounts for different marketing purposes like marketing automation, newsletters etc.
A screenshot showing multiple sending accounts.

Manage team members

Advanced roles and user permissions so you can easily control who gets access to which part of your account. This helps you allocate jobs to different team members and keep everything under control.
A screenshot showing user roles.

Take advantage of multiple API keys

Multiple API keys are available for better security. You can assign a separate API key to each application that sends email through one sending account. In case an API key gets compromised, you can easily replace it with a new one without affecting other applications.
A screenshot showing API keys.

Enterprise solutions

We help organizations design and operate efficient, secure and reliable systems for sending large volumes of emails. Leverage our technology and experience to deliver messages to your customers quickly and effortlessly. We offer proven solutions with SLA-backed high throughput rate that will suit even the most demanding enterprise requirements.
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  • You only share data that is adequate and relevant to the delivery of our service.
  • You keep the right to object and limit data processing as well as the right to be forgotten.
  • We will sign a data processing agreements (DPA) with you to ensure the data you control is properly handled.
  • You will be notified in case we should share your personal information with another company.
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Try Coresender today

Whether you need to send a few hundred emails or a few million, we’re ready to help you deliver your message. Are you ready to get started?
Start for free
or, if you have more questions, contact us.