+package Exim::Runtest;
+use strict;
+use warnings;
+use Carp;
+
+use List::Util qw'shuffle';
+
+
+# find a group name, preferrable 'mail', but
+# use some other random name if 'mail' isn't a valid group
+# name
+sub mailgroup {
+ my $group = shift;
+
+ croak "Need a group *name*, not a numeric group id."
+ if $group =~ /^\d+$/;
+
+ return $group if getgrnam $group;
+
+ my @groups;
+ setgrent or die "setgrent: $!\n";
+ push @groups, $_ while defined($_ = getgrent);
+ endgrent;
+ return (shuffle @groups)[0];
+};
+
+
+1;