Originally Posted by till
So instead of talking to change a etup which has prooven to work reliably an many systems, you shoul try to debug your mysql server by enabling mysql logging to see why postfix is not able to connect to mysql.
I did that already and have seen and when that happens, I see not even a query in the MYSQL log. The lock must have happened before. Postfix shown an error without having passed the query to MYSQL - that is what I think I see.
If it would be your server and your customers, what would you do instead?