Hey! I checked the logs and it looks like the email was bounced because it was too short - the minimum length I believe is ~20 characters. You should have received an automated response describing the problem with the post.
The min length is set to avoid insubstantial responses - “yes!” and the like. It’s easy to change if there’s consensus that e.g. one word responses should be allowed. I’m pretty neutral on the subject, though I understand the policy as super short / reaction responses can easily be misinterpreted in a forum context (and usually misinterpreted for the worse).