Thanks for the input faris.
The email address that is failing is on on dmcadmin.co.uk. That is the MX which goes to the smtp.cluster:
[root@plesk3 ~]# dig @localhost mx dmcadmin.co.uk
; <<>> DiG 9.3.6-P1-RedHat-9.3.6-16.P1.el5 <<>> @localhost mx dmcadmin.co.uk
; (1 server found)
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 19768
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 0
;; QUESTION SECTION:
;dmcadmin.co.uk. IN MX
;; ANSWER SECTION:
dmcadmin.co.uk. 86400 IN MX 5 smtp.cluster.switchmedia.co.uk.
;; AUTHORITY SECTION:
dmcadmin.co.uk. 86400 IN NS ns1.switchmedia.co.uk.
dmcadmin.co.uk. 86400 IN NS ns0.switchmedia.co.uk.
;; Query time: 24 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Thu Jun 16 10:07:05 2011
;; MSG SIZE rcvd: 109
[root@plesk3 ~]# host smtp.cluster.switchmedia.co.uk
smtp.cluster.switchmedia.co.uk is an alias for a.mx.switchmedia.com.
a.mx.switchmedia.com has address 89.207.168.36
[root@plesk3 ~]#
It was investigation of the domain switchmedia.co.uk that gave the output in the first post.
We have never hosted dmcadmin.co.uk or switchmedia.com.
If our client sends from the domain that we host, it fails. If he sends from his google mail it goes through. I think Plesk 10 chooses not to send when the MX record goes to a CNAME. The dnsstuff check we did was the mail test:
E-mail Tester results for
xxxxxxx@dmcadmin.co.uk
Getting MX record for dmcadmin.co.uk (from local DNS server, may be cached)... Got it!
Host Preference IP(s) [Country]
smtp.cluster.switchmedia.co.uk. 5 89.207.168.36 [GB]
Step 1: Try connecting to the following mailserver:
[ERROR: A CNAME appeared in the MX records; this is not valid (per RFCs 974 "Minor Special Issues" section, and 1034 section 3.6.2.
Mailservers are not required to send E-mail to smtp.cluster.switchmedia.co.uk.]
CNAME(s) I found are: [smtp.cluster.switchmedia.co.uk. CNAME a.mx.switchmedia.com.] smtp.cluster.switchmedia.co.uk. - 89.207.168.36
Step 2: If still unsuccessful, queue the E-mail for later delivery.
Trying to connect to all mailservers:
smtp.cluster.switchmedia.co.uk. [ERROR: A CNAME appeared in the MX records; this is not valid. A CNAME appeared in the MX records; this is not valid (per RFCs 974 "Minor Special Issues" section, and 1034 section 3.6.2.
Mailservers are not required to send E-mail to smtp.cluster.switchmedia.co.uk.]
Sorry that my previous posts were not clear with the actual domain that goes via switchmedia. Can you help further?