Many domain owners have an SPF record to help prevent sender-spoofing. When you enable it, mail servers are required to check if your domain is listed in the SPF record before accepting incoming mail from your server. 

Creating SPF record for Sendinblue

Here are the steps to set up SPF for Sendinblue :

• Login to your DNS management console 
• Navigate to Tools & Settings > DNS Template
• You need to edit the DNS TXT record related to SPF
• An SPF TXT record for Sendinblue will have the following syntax: 

mydomain.com    TXT  v=spf1 include:sendinblue.com ~all

• Publish this record in your DNS records section for your respective domain.  

Note: If you don’t have an SPF record previously for your domain, simply publish the above-mentioned record to enable SPF for outgoing emails using Sendinblue. If you do have an existing SPF record in your DNS, you need to modify it to include Sendinblue, as shown below:

Previous SPF record:  v=spf1 mx -all

Modified SPF record:  v=spf1 mx include:sendinblue.com ~all

• Save changes 
• Wait for 72 hours to allow your DNS to process the changes 

Finally, you can look up your record using our SPF record lookup tool, and enable DMARC for your domains: take a DMARC trial.