Setting Up Sendinblue Mailer in Fluent SMTP

You can use Sendinblue to improve your WordPress site email deliverability? Sendinblue is one of the leading mailer options for WordPress, SendinBlue is reliable and easy to set up. In this article, you will learn how to use Sendinblue mailer with Fluent SMTP.

Configuring Fluent SMTP for SendInBlue #

Hover over settings and go to Fluent SMTP Dashboard. If this is the first time you are using Fluent SMTP you will see the list of available Mailer, go ahead and select SendInBlue.

Configuring Fluent SMTP for SendInBlue

After selecting SendInBlue as the mailer, a very simple settings window will open as shown on the screenshot below.

Sendinblue Fluent SMTP

As I said, This is as simple as setting up the “From Email”, “From Name” and API Key and clicking the save button.

From Email: The “From Email” should be the email you verified with SendInBlue. Check the box to set the return path to match the from. The Return Path indicates where non-delivery receipts – or bounce messages – are to be sent. If unchecked, bounce messages may be lost. With this enabled,
you’ll be emailed using “From Email” if any messages bounce as a result of issues with the recipient’s email.

From Name: From name can be anything you want. The best practice is to use the combination of your name and company name. For example, I would choose something like “Jewel From WPManageNinja” where Jewel is the first name of the CEO and WPManageNinja is the company. The API key will be provided by SendInBlue.

How to get SendInBlue API Key: #

Log into your SendInBlue account first and then click on the account icon located at the top right corner. A dropdown panel will appear and you need to click on the SMTP & API.

How to get SendInBlue API Key

Now create a new V3 API key or use an already existing API Key.

Sendinblue API Key Fluent SMTP

Go back to your Fluent SMTP’s SendInBlue configuration panel and enter the API key and your SendInBlue Driver is ready to impact for transactional emails.

Send a Test Email #

Go to the Email Test Tab and type a from email. This should be the same “From Email” of your SendInBlue setup. This is optional and you can leave it blank also. in that case, the default SMTP Driver will be used. If you get a success message as shown below then your SMTP setup is up & running.

send test email from Fluent SMTP

Frequently Asked Questions #

How to fix “[permission_denied]:Unable to send email, Your SMTP account is not yet activated”? #

This error states that your SendInBlue account is not activated yet. To fix the issue, get in touch with the SendInBlue team. After signing up with SendInBlue you also need to activate the SendInBlue account.

Latest comments (26)

Hi Nazir, I need some advise please. I installed Fluentsmtp on my site connecting Sendinblue and it sent all the test emails. I have forms on the site for customer queries. The problem is that once somebody sends an email through the forms, where do I get them i.e the inbox ? In my webmail I find nothing.


I always get ther massege “invalid email adress” after sending the test email.
I have set up sendinblue including the API key. But there’s nothing sent.
How can I fix that?


I had first set up sendinblue API successfully. Afterward, I noticed the Fallback recommendation on a drop-down menu. I had noticed that I also had SMTP credentials in my new sendinblue account, so I thought I could use that. After completing its setup in “Other SMTP”, that SMTP setup replaced my original API setup in Fluent, saying that I could only use the email on one account. So is it necessary to have 2 independent ESP accounts in order to use a Fallback?

The plugin works well with SendInBlue except that the emails go out unformatted without any line breaks. Whereas the FluentSMTP test email comes in neatly formatted. Where do I format the emails? (Notification emails sent from WordPress when a new user signs up or when they receive a password reset link, etc)

Hi. I have entered my sendinblue API key a couple of times, and received a failure error in my FluentSMTP plugin dashboard when trying to test (and my log says all “failed”) that says just “key not found”.

Does that mean the API key? As said, it’s entered.

Any other thoughts on where my configuration might be wrong?

Hi Rachel, maybe you haven’t inserted the right API key. Please ensure that your email address is verified and insert the right API key. If it still doesn’t work, you can submit a support ticket so that our technical experts can take a look. 🙂

My domain is authenticated.
I have set up fluent smtp and copied and pasted ur api key in fluent smtp as per instruction.
But my emails are failing and it show your send in blue account is not activated yet (my domain and email both are authenticated and verified respectively in my send in blue account).

Jose Luis

I have just installed your plugin and I am trying to configure the connection to Sendinblue as per your documentation and I see two fields related to the API code.
One is :Store API Keys in DB” and the other one “Store API Keys in Config File”
The later one states that I have to copy this: define( ‘FLUENTMAIL_SENDINBLUE_API_KEY’, ‘********************’ ); to wp-config.php
Since this is not indicated in your documentation, I wonder if this is strictly necessary

Nazir Himel

You can either configure an email service from the UI itself or add the string to the WP config. Using any method works. However, if you’re not familiar with wp-config.php, I recommend leaving it untouched.

Gregg Schroeder

Hello, I’m struggling to use SendinBlue and FluentSMTP. I set up everything in SendinBlue and added the TXT dns records and authenticated them for our site, (was this necessary?)

And when I send a test email from FluentSMTP, it sends fine, but nothing shows up in the fluentSMTP email logs. At all, ever.

And I do see this warning at the top of my wp site management

The FluentSMTP plugin depends on wp_mail pluggable function and plugin is not able to extend it. Please check if another plugin is using this and disable it for FluentSMTP to work!

Possible Conflict: /home4/solarset/public_html/wp-includes/pluggable.php:171

Whenever I sent a test email it always says ‘mail delivered succesfully’ even when it was send to a non existing email address. Shouldn’t it report as being bounced then?