Your Gmail account will typically be on 2000 emails per day however this can vary on your account. Once you have sent 2000 emails your Gmail account will now put a 24 hour stop on any outbound emails. Hence the "attention" being shown on your SalesCurve dashboard.

Once the 24 hours are up you will now be able to resend any sequences stopped by your Gmail limits. 

Typically, users will not reach their limits on Gmail using our tool, however to resolve this all you have to do is simply wait 24 hours. If they turn to active you are no longer at your Gmail limit