The MX record is indeed invalid. $ host lists.bitrig.org
lists.bitrig.org mail is handled by 10 www.bitrig.org. ... so far so good, let's look at www.bitrig.org. $ host www.bitrig.org www.bitrig.org is an alias for bitrig.org. bitrig.org has address 69.39.66.4 bitrig.org has IPv6 address 2607:f790:ffff:ff15::4 bitrig.org mail is handled by 10 git.bitrig.org. ... but this is not; given the MX record at top, www.bitrig.org is required to have an A and/or AAAA record. Now look at git.bitrig.org $ host git.bitrig.org git.bitrig.org has address 69.39.66.6 git.bitrig.org has IPv6 address 2607:f790:ffff:ff15::6 ... this has an A and an AAAA. The easiest fix is to change the MX to lists.bitrig.org. IN MX 10 git.bitrig.org. On Fri, Jan 16, 2015 at 3:56 PM, Mirco Richter <[email protected]> wrote: > Just want to inform you that it is not possible to subscribe to the > mailing list from some email providers, due to a proposed non valid > MX-Record. > > For example if I try to subscribe to any of your lists from the provider > 'web.de' I get the following message: > > > ------------------------ > > This message was created automatically by mail delivery software. > > A message that you sent could not be delivered to one or more of its > recipients. This is a permanent error. The following address failed: > > "[email protected]": > no valid MX hosts found > > > ------------------------------ > > -- Christopher Vance
