Ok thanks to the wonderful Cedbobking, i have managed to successfully fix my sending issue. it was so easy, a delirious overlooking. I hope that the recieving part will be similar.
So a little more detail.....
Now what happens is:
if I send an email to my zimbra mailbox from gmail i get a response form the server saying:
However, i have checked, and checked again....
This is the mail system at host mailserver.mymailservername.com.
I'm sorry to have to inform you that your message could not
be delivered to one or more recipients. It's attached below.
For further assistance, please send mail to postmaster.
If you do so, please include this problem report. You can
delete your own text from the attached returned message.
The mail system
<firstname.lastname@example.org>: Host or domain name not found. Name service error for
name=mailserver.mymailservername.com type=A: Host not found
Final-Recipient: rfc822; email@example.com
Diagnostic-Code: X-Postfix; Host or domain name not found. Name service error
for name=mailserver.mymailservername.com type=A: Host not found
Here are some tests from my environment:
192.168.80.158 is my internal network DNS server running bind/named
[root@mailserver opt]# dig mx mailserver.mymailservername.com
; <<>> DiG 9.3.4-P1 <<>> mx mailserver.mymailservername.com
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 10738
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 0
;; QUESTION SECTION:
;mailserver.mymailservername.com. IN MX
;; AUTHORITY SECTION:
mymailservername.com. 86400 IN SOA mymailservername.com. mailserver.mymailservername.com. 42 10800 900 604800 86400
;; Query time: 0 msec
;; SERVER: 192.168.80.158#53(192.168.80.158)
;; WHEN: Tue Sep 30 02:41:28 2008
;; MSG SIZE rcvd: 89
Here's my /etc/hosts file
something like this:
127.0.0.1 localhost.localdomain localhost
192.168.80.166 mailserver.mymailservername.com mailserver
192.168.80.158 dnsserver.mymailservername.com dnsserver
Still no joy..................