Exim's command language is complex and hard to get right, so adjust as
necessary to make this behave in a predictable way. Also use explicit
true/false to make condition= not upset.
# disabled accounts don't even get local mail.
deny domains = +virtual_domains
condition = ${if exists {${extract{directory}{VDOMAINDATA}{${value}/mail-disable}}}\
- {lookup{${extract{1}{-}{$local_part}}}lsearch;${extract{directory}{VDOMAINDATA}{${value}/mail-disable}}}\
+ {${lookup{${extract{1}{-}{$local_part}}}lsearch{${extract{directory}{VDOMAINDATA}{${value}/mail-disable}}}{true}{false}}}\
{}}
message = ${lookup{${extract{1}{-}{$local_part}}}lsearch{${extract{directory}{VDOMAINDATA}{${value}/mail-disable}}}{$value}}