use warnings;
use strict;

my $str =
'May  2 04:06:15 lon.mail.net exim[17905]: 2012-07-03 07:06:15 1SPPtO-0004en-PS <= me@ours.co.uk H=smtpout.mail.com [22.5.10.4] I=[6.5.14.4]:25 P=esmtp S=13333 id=6aeca3b79b8892d6105dab131c76f066@localhost.localdomain T="Half price offer"';

my ( $e_mail, $ip ) = unpack "x82A13x21A9", $str;
print "EMAIL: ", $e_mail, "\nIP: ", $ip, $/;

# OR

while (<DATA>) {
    my ( $e_mail, $ip ) = unpack "x82A13x21A9", $_;
    print "EMAIL: ", $e_mail, "\nIP: ", $ip, $/;
}

__DATA__
May  2 04:06:15 lon.mail.net exim[17905]: 2012-07-03 07:06:15 1SPPtO-0004en-PS <= me@ours.co.uk H=smtpout.mail.com [22.5.10.4] I=[6.5.14.4]:25 P=esmtp S=13333 id=6aeca3b79b8892d6105dab131c76f066@localhost.localdomain T="Half price offer"