How to send emails with Coresender SMTP

When you have at least one sending account and one verified sending domain, you’re ready to integrate Coresender with your application. 

First of all, you should decide whether to use API or SMTP. In both cases, your emails will get delivered, but both methods are very different and each has its pros and cons. 

API offers more features but some level of coding is required. Here’s the guide on How to send emails with Coresender API.

SMTP won’t give you some advanced features, but the integration much simpler. In fact, linking Coresender SMTP relay service with your app requires just a few steps. 

In this article

Step 1 – Grab your SMTP server information

  1. Visit the Coresender user panel, click on Sending accounts and click on the sending account you want to use
  2. Click on SMTP server tab and select the API Key from the list to reveal the Password

Step 2 – Configure Coresender with your app

We have a list of ready-to-follow SMTP integration guides for some popular apps. 

If you can’t find your app on the list, no worries. The setup is pretty easy and almost identical for most apps. 

Simply enter the following information into your app’s SMTP Server Settings:

  • SMTP Host -
  • Port - choose either 587 or 465
  • Encryption – For port 587, choose STARTTLS (sometimes just TLS) and for port 465, choose SSL
  • Username – use the name from the "SMTP server" tab (as shown above)
  • Password – the password is below the USERNAME in the "SMTP server" tab (as shown above)
  • From name – use the name you want to display in your email
  • From email – you can only use an email address within the domain that you’ve added and verified with Coresender

In case you should have any problems with the integration or at any point you’re not sure what to do, just let us know at and we’ll be happy to help you.

Step 3 – Send a test message

Once all the credentials are in place, you’ll be able to send a test email. In fact, your application may have a “Send test” function.

Another way in which you can test the configuration is by sending a regular email from your app. The example below shows a test message we’ve sent using Coresender SMTP.

Coresender lets you track messages. You can visit the Activity section of the Coresender control panel to see e.g. the time of send and the time of delivery of the message. 

Congratulations! You've sent your first message.

Now, you're ready to start testing Coresender using the free developer plan. Of course, at any moment you can request your organization to be approved by Coresender and begin using the service in your production environment.