I want any records ... that have a given email address in the 4th field

In that case, a direct string comparison is probably better (or at least simpler...) than a regex, along the lines of:

my $adr = 'example@hotmail.com';
my @goodrecs;
for (@recs){
   push @goodrecs, $_ if (split /:/)[3] eq $adr;
}
[download]

This can doubtless be 'grepped', but I don't see why you should care...

dave