Sending Email with SMTP

The CloudMailin SMTP system allows you to use SMTP to send transactional email. When sending email with SMTP you can still benefit from our queues and priority, our tagging and all of our analytics systems.

Often web frameworks and applications have systems embedded to allow sending email over SMTP. Using SMTP also allows a simple configuration change to move providers in most cases.

We recommend sending both Plain and HTML email parts when sending your transactional emails. Once you've setup a domain to start sending you'll need an outbound account to get your SMTP connection details:

Field Value Details
Host provided Your SMTP host will be provided on your account page.
Port 587 (recommended), 2525, 25 We accept mail on multiple ports. In case one is blocked by your host try a different port.
STARTTLS required Start TLS must be used to begin a encrypted session before we will allow authentication to take place.
Auth login, plain We require login or plain auth once an encrypted sesssion has been established.
Username provided Your account page will show your username.
Password provided Your account page will show your password.

Once you've sent a message the SMTP transaction will reply with the message-id of the message to use for bounce tracking if required.

250 Thanks! Queued as: f78b876d-dd97-4e10-9a61-067f98044cc7

Queues, Priorities and Tagging Support

Using SMTP you can add additional headers to your emails to help control things like the queue we use to send the email and tags to allow analysis/filtering in the dashboard. More infromation about setting these can be found in the Setting SMTP queue priority and Tagging documentation.


There are a number examples below for specific languages and frameworks to get started sending email over SMTP: