${if eq {1}{1}{yes}{${lookup{xx}lsearch{/non/exist}}}}
match_address: ${if match_address{a.b.c}{a.b.c}{yes}{no}}
****
+exim -d-all+expand+noutf8 -be
+primary_hostname: $primary_hostname
+match: ${if match{abcd}{\N^([ab]+)(\w+)$\N}{$2$1}fail}
+match: ${if match{wxyz}{\N^([ab]+)(\w+)$\N}{$2$1}fail}
+${if eq {1}{1}{yes}{${lookup{xx}lsearch{/non/exist}}}}
+match_address: ${if match_address{a.b.c}{a.b.c}{yes}{no}}
+****
# Sender host name and address etc, all unset
exim -be
-be Sender host name and address etc, all unset