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Troubleshooting issues with the SMTP

In this article, we will go over the common problems you may encounter when you are using your SMTP with Sendinblue and the steps you can take to fix them.

Your emails are not being sent

There are a few possibilities as to why they are not being sent:

This service has not been enabled for your account

To be able to use the Sendinblue SMTP, the option must be activated on your account. You can click here to read more about it.

If you see an orange banner like the one below, this means that the Sendinblue SMTP has not been activated for your account. You can create a ticket from your account or contact us here to put in a request and have it activated for your account.


Your hourly sending bandwidth has been reached

Sendinblue applies an hourly sending bandwidth to maintain the sender's reputation of new users of shared IPs. You can read about it in detail here.

You can easily check if you have reached your limit, by taking a look at the indicator in the left-hand menu under Quota.


❗️ Important
This quota does not apply to users with dedicated IP addresses.

All your credits have been used

Your transactional emails will not be sent if all of your credits have been used. They will be held for a maximum of 48 hours until additional email credits have been added to your account. You can easily check if your email credits have been used up in the left-hand menu under your Plan.


The selected sender for your template is not valid

If you have recently bought or configured a dedicated IP, the templates used for your transactional emails might not have been correctly updated and are still being configured for your former senders.

To check that your templates have been configured with the correct sender:

  1. Go to Transactional > Template on your account.
  2. Edit the From Email field in the relevant email templates.

Your settings are incorrect

Depending on the encryption you use, you need to use a specific port. For non-encrypted connections, you may use port 587 or 2525. For encrypted connections, use port 465 with an SSL or TLS encryption.

Also make sure you are using the SMTP key and not the API key.


  • Domain name: (leave this field empty)
  • SMTP server:
  • SMTP user: your Sendinblue login (case-sensitive)
  • SMTP password: You can find it under Your account name > SMTP & API > SMTP.
  • Encryption : (leave this field empty unless you’re using port 465, for which you should select SSL or TLS encryption)
  • Port : (the one you choose)
💡 Good to know
You can read more about how to configure the SMTP server here.

If you are not able to authorize the domains, the following Sendinblue IPs need to be added to your whitelist:, and

The Sendinblue platform is temporarily unavailable

The Sendinblue platform may be temporarily unavailable. You can check the status of the Sendinblue platform by going to the Status page.

You are unable to log into the Sendinblue SMTP relay

There are a few possibilities as to why you are unable to log in:

Relay access has been refused

Authentication may have failed: check your API key, which you can find here.

Login is not possible

The Sendinblue server may be temporarily unavailable. You can check the status of the Sendinblue platform by going to the Status page.

Your emails are not being sent by the correct IP

If your emails are not being sent by the correct IP:

Your dedicated IP is not configured for the SMTP

To check that your dedicated IP has been correctly configured for the SMTP

  1. Go to the Dedicated IP page.
  2. Click Manage. If you can see the option Use this IP for transactional emails, then it has not been associated with transactional emails. 
  3. Just click Use this IP for transactional emails to associate it.

🤔 Have a question?

If you have a question, feel free to contact our support team by creating a ticket from your account. If you don't have an account yet, you can contact us here.