Here is the communication we received from our email supplier
Dear User,
Thank you for providing information and direct contact.
Please be advised that at the moment we are in process of implementing new security measures in regards of anti-abuse actions, which entails calibration of newly deployed tools. Considering new testing nature of mentioned tools, unfortunately, in some cases, it leads to technical collisions. After review of the issue with your account, we have applied necessary actions/measures in order for it (your account) not to face anything similar in future, as your account has no relation to abuse. Your account operates in full status, and should not face anything similar.
Accept our apologies for possible inconveniences caused.
Sincerely,
Igor
Anti-Abuse Team
turboSMTP