I get the message "Unusual activity detected. Your account is locked from sending emails."

Apparently my account was hacked and sent spam for a few minutes 12 hours ago.

I ran a virus scan, changed to a longer password and added 2FA and have been trying all day to get my account unblocked. As instructed on the error page, I sent an email (ironic) from another account to support@zohomail.com but no answer.

This seems like the wrong place to get this fixed, but support is MIA.  How long will I be blocked from sending email? What do I need to do to get going again?