I think queue is a good suggestion. There was a great preso at drupalcon sf by jvandyk re: batch v. queue, in case you wanted a high-level on the typical use cases for each.<br><div><br></div><div><a href="http://sf2010.drupal.org/conference/sessions/batch-vs-queue-api-smackdown">http://sf2010.drupal.org/conference/sessions/batch-vs-queue-api-smackdown</a></div>

<div><br><br><div class="gmail_quote">On Tue, Jun 1, 2010 at 10:58 AM, Andrew Berry <span dir="ltr">&lt;<a href="mailto:andrewberry@sentex.net">andrewberry@sentex.net</a>&gt;</span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">

<div class="im">On 2010-06-01, at 2:09 AM, Chris Skene wrote:<br>
<br>
&gt; Why not try using the Batch API instead?<br>
<br>
</div>Better yet, use <a href="http://drupal.org/project/job_queue" target="_blank">http://drupal.org/project/job_queue</a> so that your user doesn&#39;t have to wait for each email to be sent.<br>
<font color="#888888"><br>
--Andrew</font></blockquote></div><br></div>