Sending mail Blocked due to security reason: mail rated exceeding limits

Sending mail Blocked due to security reason: mail rated exceeding limits

As title says, I am blocked from sending any mail, either from web client or my IMAP client Thunderbird.

Please let me know what needs to be done to make my account functional again.

The only unusual thing is that I started using Thunderbird, but it seems unlikely this would be related, right??

I've also sent an email to support@zohomail.com

thank you
Steve.