<div dir="ltr"><div class="gmail_extra"><div class="gmail_default" style="font-family:tahoma,sans-serif">I'm finding someone to check into this for you and will let you know what I find out.</div><div class="gmail_default" style="font-family:tahoma,sans-serif"><br></div><div class="gmail_default" style="font-family:tahoma,sans-serif">Thanks,</div><div class="gmail_default" style="font-family:tahoma,sans-serif">John</div><br></div><div class="gmail_extra"><br><div class="gmail_quote">On Tue, Nov 1, 2016 at 7:50 AM, Shane Kerr <span dir="ltr"><<a href="mailto:shane@time-travellers.org" target="_blank">shane@time-travellers.org</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div id=":1nw" class="a3s aXjCH m1582027d0f303868">I have been running my own e-mail server for many years now, and have<br>
been native IPv6 for... maybe 5 or 6 years?<br>
<br>
I never have any problems, except for delivering to Comcast users. I<br>
get bounces like this:<br>
<br>
A message that you sent could not be delivered to one or more of its<br>
recipients. This is a permanent error. The following address(es) failed:<br>
<br>
<a href="mailto:xxx@comcast.net">xxx@comcast.net</a><br>
SMTP error from remote mail server after initial connection:<br>
host <a href="http://mx2.comcast.net" rel="noreferrer" target="_blank">mx2.comcast.net</a> [2001:558:fe21:2a::6]: 554 <a href="http://resimta-ch2-08v.sys.comcast.net" rel="noreferrer" target="_blank">resimta-ch2-08v.sys.comcast.<wbr>net</a> comcast ESMTP server not available<br>
<a href="mailto:yyy@comcast.net">yyy@comcast.net</a><br>
SMTP error from remote mail server after initial connection:<br>
host <a href="http://mx2.comcast.net" rel="noreferrer" target="_blank">mx2.comcast.net</a> [2001:558:fe21:2a::6]: 554 <a href="http://resimta-ch2-08v.sys.comcast.net" rel="noreferrer" target="_blank">resimta-ch2-08v.sys.comcast.<wbr>net</a> comcast ESMTP server not available</div></blockquote></div><br><br></div></div>