use keep_environment and add_environment или Suggested action: use keep_environment

Для exim чтоб логи печень не садили типа этого:

WARNING: purging the environment.
Suggested action: use keep_environment and add_environment.

.ifdef MAIN_KEEP_ENVIRONMENT
keep_environment = MAIN_KEEP_ENVIRONMENT
.else
# set option to empty value to avoid warning.
keep_environment =
.endif
.ifdef MAIN_ADD_ENVIRONMENT
add_environment = MAIN_ADD_ENVIRONMENT
.endif