Your mail content, past history of your account, your subject line, all have an impact on whether your emails will be considered spam or not. While they take all necessary steps to ensure the reputation of our IP, they request you to follow email marketing best practice to ensure your account does not get suspended, and/ or your emails are not considered spam. Another important principle that will ensure your mails are not considered Spam is to send emails ONLY to engage your subscribers who opt-in for receiving communication from you.