SMTP vs API: Advantages and Disadvantages

Doppler Relay allows you to integrate your application, website, or eCommerce in two different ways: SMTP or API. Based on the needs of your business or features of your application you can choose one to the other.

Let’s see the advantages and main differences between them.


Let’s see below the main advantages of the SMTP connection

Easy to connect

The SMTP connection has among its main advantages its ease of installation, since to start using Doppler Relay for your Transactional Emails you only have to change the SMTP credentials and in minutes you can have integrated your system with ours.

Connects to any system

Another advantage of the SMTP connection is its flexibility with existing applications, it has no restrictions, so it doesn’t matter what system you have just have to include the SMTP information of your Doppler Relay account and will be working in just minutes.

Doesn’t  involve any development from your side

If you don0t have a team or a person available for to create the triggers to use our API, then our SMTP server is a great solution. 

Common steps such as modifying existing messages by adding a custom header to set the campaign for different message streams, or enabling the tracking of the opening or clicking tend to be significantly less complex than starting to use the API .


Now let’s take a look at the advantages of connecting through API Rest.

Flexibility in sendings

Using our API Rest allows you a greater flexibility in automating the various submissions that your application or website triggers.

Deliverability speed

If you use the API connection for your Transactional Emails you may see an improvement in delivery speed of at least a few seconds. While the SMTP connection allows fast delivery of emails, thanks to our API this time could be optimized.

Better on a larger scale

The Rest API has a greater robustness that against a large number of shipments can provide greater security and deliverability. It allows to obtain the results of the sendings.

Using the Rest API you can get the status of the shipments and take them to your own platform and consume them directly there.

Greater security

The Rest API allows you to add an additional layer of security to your program using API keys. API keys allow you to generate an authentication credential separate from your user password, which significantly reduces the possibility of someone using your account sending spam or phishing.

Other Benefits

  • You do not have to deal with MIME because we’ll ride it on our side.
  • You can simply use a library of requests available for the language you use.
  • HTTP is allowed by all but the most restrictive firewalls


Was this article helpful?
Help us improve our assistance by rating it
1 Star2 Stars3 Stars4 Stars5 Stars

Leave a Reply

Your email address will not be published.

I accept Doppler's Privacy Policy.

Doppler informs you that the personal data that you provide to us when completing this form will be treated by Doppler LLC as responsible for this web.

Purpose: To allow you to make comments in our help center.

Legitimation: Consent of the applicant.

Recipients: Your data will be saved by Doppler and Digital Ocean as hosting company.

Additional information: In the Doppler Privacy Policy you’ll find additional information about the collection and use of your personal information by Doppler, including information on access, conservation, rectification, deletion, security, cross-border data transfers and other issues.