Mail sending paused due to “unauthorized” mailaddress while mail is authorized

MailPoet is constantly showing an error message: “Automatic mail sending was paused due to use of an unauthorized e-mail address. Authorize the e-mail-address or change it.” (Roughly translated.)
But the thing is that the e-mail I’m using already is authorized and it’s also shown as being authorized in my MailPoet Account when I’m following the “Authorize it”-link.

Can ANYONE help me? The support isn’t very responsive.