use strict;                                                                     
use warnings;                                                                   
use autodie;                                                                    

my @test_svc = (
    "test\@customer1.service", "test\@customer2.service",
    "test\@custome3.service",  "test\@customer4.service",
    "test\@customer5.service", "test\@customer6.service",
);

my @customers = qw/ customer1 customer2 customer33 customer4 customer5 /;

for my $cust (@customers) {
    if ( my ( $matched ) = grep $_ =~ $cust, @test_svc ) {
        print "$cust matches:\t $matched\n";
    }
    else {
        "no matches for $cust\n";
    }
}