I believe you need to add a second newline after the Subject, like: 
$s->datasend("Subject: $subject\n\n");

[download]

Some mail clients (maybe most, I dunno) need to see a completely blank line to separate the headers from the message body.

- Matt Riffle

In reply to Re: about Net::SMTP by mattriff
in thread about Net::SMTP by hdeng419

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