You could use Mail::Send to send your mails, so you wouldn't have to care about creating an RFC-compliant header and stuff. IMHO you should send mails in plaintext whenever possible because all MUA's can display them, which is not true for HTML. 
use Mail::Send;
$msg = new Mail::Send;
$msg->to('user@host');
$msg->subject('example subject');
$fh = $msg->open('sendmail');
print $fh "Body of message";
$fh->close;

[download]
What you could do to make registration easier is: Allow the user to reply, keeping subject intact. So he hasn't go trough the hassle of fireing up his browser and visit any links.

In reply to Re: email activation link by timos
in thread email activation link by boboson

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