removing a section from a configuration file using bash

script.sh

AMAVIS_CONFIG_HEADER="# Amavis - dockermail - start"
AMAVIS_CONFIG_FOOTER="# Amavis - dockermail - end"

function remove_amavis () {
  # main.cf
  if grep -q "$AMAVIS_CONFIG_HEADER" "$POSTFIX_MAIN_CF"; then
    sed "/$AMAVIS_CONFIG_HEADER/,/$AMAVIS_CONFIG_FOOTER/d" "$POSTFIX_MAIN_CF" -i
  fi
  # master.cf
  sed '/^pickup/,/^cleanup/{//!d}' "$POSTFIX_MASTER_CF" -i
  sed "/$AMAVIS_CONFIG_HEADER/,/$AMAVIS_CONFIG_FOOTER/d" "$POSTFIX_MASTER_CF" -i
}