On 4/13/2010 2:16 AM, Bob Eastbrook wrote:
I use wildcard MX records for mail, and a wildcard CNAME for web traffic. For example:*.example.com = MX record for mail.example.com *.example.com = CNAME myapp.appspot.com
MX records must not point to a CNAME.
Email to b...@foo.example.com gets delivered to mail.example.com, and web traffic to http://foo.example.com goes to myapp.appspot.com. I use instructions from Wietse from a post I made on Dec 31, 2009: http://www.pubbs.net/200912/postfix/75444-virtual-domains-for-wildcard-mx-records.html. This works for all mailers I've found except for Yahoo Mail. Mail sent from Yahoo is rejected with: <b...@foo.example.com>: [ip.number.of.mailserver] does not like recipient. Remote host said: 554 5.7.1<b...@myapp.appspot.com>: Relay access denied Giving up on [ip.number.of.mailserver].
Original RFC822 said that mail to a CNAME should be rewritten to the canonical name. Later RFC's relaxed that, but some mailers still behave that way.
Don't use a CNAME for email. That will fix the problem. -- Noel Jones
