Sendinblue attaches great importance to confidentiality and encrypts all connections as much as possible between servers and customer emails (like Gmail):
- for incoming connections, we recommend you send your emails through our SMTP using port 465, which uses the SHA256 encryption protocol.
- for outgoing connections, we always try to use the TLS protocol whenever it is available. If it is not available, we use the insecure standard SMTP protocol.
Note: if you use Gmail, you can check if your emails have been encrypted. Non-encrypted emails appear with an open padlock as shown in the image below: