Actually, you don't have to worry about all that.  The Amazon account (at least here in the US and I imagine it is done everywhere) has to have an email address on a whitelist in your account before the system will forward an emailed document/book to your Kindle.  In my account, only documents sent from my own email address can get through.
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<div>So, all you need is a nice big NOTE on the page to remind people to whitelist the PG email address if they want the book emailed directly to their Kindle.</div>
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<div>Josh<br /><br />
<p>On Oct 30, 2012, <strong>Marcello Perathoner</strong> &lt;marcello@perathoner.de&gt; wrote:</p>
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<blockquote class="email_quote" style="border-left: 2px solid #267fdb; margin: 0pt 0pt 0pt 1.8ex; padding-left: 1ex;">On 10/30/2012 01:33 AM, Greg Newby wrote:<br /><br />&gt; We haven't emailed books before, but I<br />&gt; agree it might be desirable.  I can think of some details<br />&gt; that matter (i.e., preventing emailing books to strangers;<br />&gt; books that are too big for email).<br /><br />That would be very hard to do in a secure way.<br /><br />We'd have to check each person's email to avoid people spamming other <br />people's Kindles with big files or with unappropriate content.<br /><br />We'd have to implement a full fledged user system, with email address, <br />password and email confirmation. This is confidential data and quite <br />impossible to keep secret on a system like ibiblio, where all web <br />servers run as user nobody.<br /><br />Furthermore Amazon could easily block that if they wanted because our IP <br />adress would be known. They probably have a big spam filter already that <br />would block us anyway.<br /><br />And it would be a wrong political signal. Why should a volunteer <br />organization work hard to make a the crappy devices of a multi-billion <br />company user-friendly? After all it is not PG being user-unfriendly but <br />Amazon. Our politics should be to make people complain to Amazon.<br /><br /><br />The solution is quite easy: Ask Amazon to implement a function in Silk <br />that lets user save books to the "Books" tab. Make lots of people ask.<br /><br /><br /><br /><br />Regards<br /><br />-- <br />Marcello Perathoner<br /><a class="parsedEmail" href="mailto:webmaster@gutenberg.org" target="_blank">webmaster@gutenberg.org</a><br />_______________________________________________<br />gutvol-d mailing list<br /><a class="parsedEmail" href="mailto:gutvol-d@lists.pglaf.org" target="_blank">gutvol-d@lists.pglaf.org</a><br /><a class="parsedLink" href="http://lists.pglaf.org/mailman/listinfo/gutvol-d" target="_blank">http://lists.pglaf.org/mailman/listinfo/gutvol-d</a><br /></blockquote>
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