Postfix stable release 3.1.3 and legacy release 3.0.7 

Fixed with Postfix 3.1.3 and 3.0.7:

. The Postfix SMTP server did not reset a previous session's 
  failed/total command counts before rejecting a client 
  that exceeds request or concurrency rates. 
  This resulted in incorrect failed/total command counts 
  being logged at the end of the rejected session.

. The unionmap multi-table interface did not propagate table lookup 
  errors.

. The documentation was updated with a workaround for false 
  "not found" errors with MySQL map queries that contain UTF8-encoded 
  text. The workaround is to specify "option_group = client" in 
  Postfix MySQL configuration files. This will be the default setting 
  with Postfix 3.2 and later.