postfix: Use pgsql functions in query templates where possible.
# All parameters are described in pgsql_table(5) / PGSQL PARAMETERS
#
# The hosts that Postfix will try to connect to and query from.
hosts = localhost
# The user name and password to log into the pgsql server.
user = postfix
password = some_password
# The database name on the servers.
dbname = mailsys
# The SQL query template used to search the database
# Use this VIEW-based template if you didn't create the pgsql function
# `postfix_transport_map'.
#query = SELECT transport FROM postfix_transport WHERE address='%s'
# the recommended, function-based template
query = SELECT transport FROM postfix_transport_map('%u', '%d')