Something

Got the following message in the postfix logs while trying to set-up a mail server based on postfix and mysql on a ubuntu 7.10 system:

warning: connect to mysql server localhost: Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock'

In the /etc/postfix/mysql*.cf files I had tried two values for the hosts parameter that caused this error:
  hosts        = unix:/var/run/mysqld/mysqld.sock
and
  hosts        = localhost

The value that worked was:
  hosts        = 127.0.0.1