Stop updating dns record
The Postfix configuration file specifies a very small subset of all the parameters that control the operation of the Postfix mail system.Parameters not explicitly specified are left at their default values.Unnecessary changes are likely to impair the operation of the mail system.
To recover delete (NOT: truncate) the file and do "postfix reload".
Postfix daemon processes do not use root privileges when opening this file (Postfix 2.5 and later).
The file must therefore be stored under a Postfix-owned directory such as the data_directory.
The expression "$" is replaced with "value1" when "$name" is non-empty, and with "value2" when "$name" is empty.
The "" is required for "value1", optional for "value2".