It is technically impossible to guess a sufficiently long random string of characters. This would take several hundreds of years with current means using an unlimited number of attempts. It has also been proven that if user constraints are too heavy, besides being an inconvenience, users are more likely to use a weak password or write it down in case they forget it.
This is why the only constraint for creating a password on SendinBlue is that it has at least 8 characters.
You then need to define a password that cannot be guessed by avoiding common passwords such as “mypassword”, “1234567890”, “qwerty1234”, etc. or an obvious combination of characters using birth dates or your children’s names for example. We recommend you use mnemonics to help you remember a random string of characters or better still, use a password manager (Dashlane, Lastpass, etc.), which allows you to generate a different password for each service.
Sendinblue hashes all passwords before storing them. It is therefore totally impossible for someone to retrieve any of the data to which they have access, including our teams.