Assuming the date, time, email address have no whitespace:

use warnings;
use strict;

my $line = '2011-01-01 15:34:554 some words and numbers then email@hos
+t.com';
my @tokens = split /\s+/, $line;
print join ' ', @tokens[0..1,-1], "\n";

__END__

2011-01-01 15:34:554 email@host.com
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