Sending test email to Mailosaur

Learn how to send emails to Mailosaur for testing and demonstration purposes.

Before you begin

  • If you don’t already have one, create a Mailosaur account.
  • You will also need to choose what server you want to send email to. Servers allow you to group tests together (for example, by project, environment, team, etc.)

Test email addresses

When developing and testing products, you will often need a set of throwaway email addresses to test features, workflows, and email content itself.

How do I create test email addresses?

You don’t need to create email addresses. Instead, every server within your account has its own, unique domain name, and any email sent to this domain will be captured.

For example, if your server had the domain, then every one of these email addresses will work, with no setup required:

# Using build numbers

# Using random user names

# Using a random string

You can make up an email address pattern that works your needs. However, if you just want a random address each time, Mailosaur’s client libraries each provide a helper method to generate one for you.

You can use these addresses in the same way you would any other email address.

Locating the domain name for a server

You can locate the domain name of a server by following these steps:

  1. Go to the Servers page in the Mailosaur Dashboard.
  2. Click on a server.
  3. In the page that appears, the server domain is shown in the top-right corner of the screen.

Sending via SMTP

Every server is a full featured virtual SMTP server. This means that instead of using test email addresses, you can point your product directly to your server via SMTP.

This is useful in cases where you want to prevent staging environments from sending email to real customers.

Using SMTP

To configure your product, you will need to change several settings. The values for your server can be found on the server settings page.


This is the address for your virtual SMTP server.


All valid SMTP ports are supported.

Note that many networks block outbound connections on port 25 by default.


Mailosaur servers require SMTP connections to be authenticated. This means that you must provide a username and password when connecting via SMTP.

SMS Testing

  • How to allocate a number
  • How to send an SMS message
  • Country support/regulations
  • The fact that SMS works the same as email, just that only the Text body gets populated and the phone not email of sender/receipient gets populated
  • Limits/restrictions
  • [Cards] pointing to ‘writing tests’ content
  • Troubleshooting