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<font color="#9FA2A5"><span style="padding-left:6px">Thursday,
February 20, 2014 9:47 AM</span></font></div></div></div>
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<div class="gmail_quote"><snip><div><br></div><div>With my
"user" hat on, I think this is fair. What would the subscription
rejection look like?</div></div>
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Since the issue doesn't lie with the SUBSCRIBE itself but rather with
server configuration, a 500 response seems appropriate. There would also
be an error message logged to indicate more specifically what went
wrong (Think something like "Subscription to mailbox 'foo' rejected
since endpoint 'bar' is already receiving notifications").<br>
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