A post ban means that a user is blocked from asking new questions, or posting new answers.
A post ban is an automated ban (unlike an account suspension which is a manual temporary penalty).
Possible error messages include:
Sorry, we are no longer accepting questions [answers] from this account.
Visit the FAQ for guidance about what to do in such situations.
- How does Stack Exchange attempt to prevent low-quality questions and answers?
- Why is the system asking me to wait a day or more before asking another question?
- How to ask a "good" question on CrossValidated?
- How should questions be answered on Cross Validated?
Reference: imported excerpt and adapted wiki from the Meta Stack Exchange site.