+# Environment
+# settings
+FOO=foo FOO1=foo1 FOO2=foo2 BAR=bar BAR1=bar1 BAR2=bar2 exim -bP keep_environment add_environment
+****
+# result via -bP environment
+FOO=foo FOO1=foo1 FOO2=foo2 BAR=bar BAR1=bar1 BAR2=bar2 exim -bP environment
+****
+# result via -n -bP environment
+FOO=foo FOO1=foo1 FOO2=foo2 BAR=bar BAR1=bar1 BAR2=bar2 exim -n -bP environment
+****
+# result via perl_at_start
+FOO=foo FOO1=foo1 FOO2=foo2 BAR=bar BAR1=bar1 BAR2=bar2 exim -ps -be ''