I'm more of a fan of stuffing the customer info into a hash

the stuff in <readmore> tags is not as interesting

#! /usr/bin/perl
use strict;
sub send_spam { print @_; }
my $_mergeFields = "##fname##;##lname##;##email##;##phone##;";
my $_list_to_send_to = "Richard;Smith;myemail\@testmail.com;8005551212
+;|Toby;Johnson;email2\@testmail.com;8885551212|Chanty;Perkins;another
+\@test.com;8665551212;";
[download]

# trim the # marks 
$_mergeFields =~ s/#//g;
# list of field names                  
my @field_names = split ';', $_mergeFields;
# list of lines from the data
my @records     = split /[|]/, $_list_to_send_to;

my $template = q[
[download]

    dear ##fname##
    great prices in \|iaqra and molex watches available
    speial offer for you now

    exclusive offer sent to ##email##
[download]

];
foreach( @records ) {
    my $message = $template;

    # hash to fill with customer information
    my %customer_record;

    # use a hash slice to populate it, 
    #  we now have keys fname lname email and phone
    @customer_record{ @field_names } = split ';', $_ ;

    # neat, a one line templating engine.
    $message =~ s/##$_##/$customer_record{$_}/g for keys %customer_rec
+ord;

    send_spam $customer_record{email}, $message;

}
[download]

Update

1. I won't ever use <readmore> tags for code folding again
2. It's nice that my answer is in some way related to the question, as well as TIMTOWTDI