In order to use the mySupport and to comment in the forum, you must have a verified email address. When you signed up for your account, it sent a verification email. Please check your email systems, including your spam folders, for an email from registration@meshiq.com. Once you verify your account, then you can just click on Sign in again and this time it will log you in.
Note that some email addresses, such as gmail.com, yahoo.com, live.com and hotmail.com are not allowed and cannot be verified.