This is most likely related to an issue with your login credentials. Please make sure that your username and password are correctly configured. Those are exactly the same as the ones you use to log in to our service.
If you are unable to find them, please log a ticket with your email address and we will create a new password for you.
If you are sure that your username and password are correct, this error might come from its automated deactivation by our security system. First check that you still have credits available in your account. If you don't, buying a package will solve the problem.
If this doesn't help either, you might have been deactivated for spam. Our system detects spam issues and blocks accounts triggering them automatically. As we operate shared IPs, we have to do this to protect our customers from landing in the spam folder because of another sender.
You can log a ticket on this site to ask us to reverse this decision. In order for us to reopen your account, please provide us with the following information:
A brief description of your business
The kind of email list you are using (opt-in, shared, purchased, ...)
One of your templates as an attached file
Once we have that additional information, we’ll review your application within 1 business day.