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<body><div>On Sat, 10 Jan 2015, at 09:33 PM, Patrick Goetz wrote:<br></div>
<blockquote type="cite"><div>How often does it happen that the same message is being delivered twice?<br></div>
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<div>Quite often when mailing lists are involved. You might get a reply addressed to you directly and another one via the list. Or if you're sending to a list, you might get a copy from the list when you already have the message in your sent folder. In both those cases it can be useful for the second copy to be dropped.<br></div>
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<div>The major problem with it in my experience is that you might actually prefer the copy of the message that came through the list. For me that's usually because I wanted DKIM headers or similar. Most of the time though its a nicer experience for users, which is why we quite deliberately have it enabled at FastMail.<br></div>
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<div>Cheers,<br></div>
<div>Rob N.</div>
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