You may have tried to send an email and you have noticed your account is blocked. There are several reasons why this could be. 

If you have just signed up for an account we require all onboarding items be completed before you can send and therefor the block is there to make sure you have finished all onboarding items before clicking send.
Here is a document on the onboarding items

Once you have completed the onboarding items please reach out to us using the chat icon on the bottom right of your panel. 

If you already onboarded and you were sending in your account and all of a sudden it is blocked this could be due to something else in your account causing it. Its possible there is an issue with your sending domain and the account is blocked to prevent any further issues with your account. We normally post a message stating this so look for this message in your chat.