[zcs 5.0.6]outgoing email is error

[lananhbin]

let me explain my situation !

my zcs running on centos 5.3. it can receives email well but

when i send email to a user of yahoo (or gmail or ...). sometimes it's ok but i often have a error :

host or domain name not found. name service error for name=yahoo.com type=mx: host not found, try again (1 messages)

i'm sure that user is existing. i try to requeue it but it's doesnt work.

and if i reboot centos , emails will go smoothly.

i checked logs ( zimbra.log and mailbox.log but it seems no error

pls give me some advice. i searched on forum and google but i found nothing !

thanks in advance!

[phoenix]

host or domain name not found. name service error for name=yahoo.com type=mx: host not found, try again (1 messages)

That error means that the domain can't be resolved by DNS, you would appear to have no response from your DNS server for that domain lookup. Does all external email delivery fail?

[lananhbin]

no ! sometimes, some of emails i send to yahoo.com is ok . but most of them isnt . when i log in admin console then click to "mail queue". they appear "defered" because of the message above . and if i reboot the machine,all of email will be sent well.( but tomorrow, when i check it again. it will be happened again T_T )

my centos is behind a firewall. and it is NATed. i installed "split dns" as the guide on wiki zimbra page. i'm toptally confused !

[phoenix]

Originally Posted by lananhbin

no ! sometimes, some of emails i send to yahoo.com is ok . but most of them isnt . when i log in admin console then click to "mail queue". they appear "defered" because of the message above . and if i reboot the machine,all of email will be sent well.( but tomorrow, when i check it again. it will be happened again T_T )

When a message is sent from ZImbra it needs to do a DNS lookup for the address, the error you've posted shows that it can't find one for some reason and that's why they're deferred - this is a DNS problem. You can verify this, when the error occurs ssh into your zimbra server and ping the domain that's having the problem and see what response you get.

Did you set-up your Split DNS server on the zimbra server? You might also have a NIC connection problem it might also be a problem of the forwarders you're using not being abailable, whichever one it is this is not a Zimbra problem with that error message.

[lananhbin]

i seted up a "split dns " server on zimbra ! i understand what u mean. i will check it

i also have a question releated to my problem. in admin cosole, my "Web mail MTA Hostname" in "MTA" tab isnt "localhost" or my machine name . it's "mail.mydomain"- a subdomain of my domain ( not my zcs hostname or something ). can it cause this problem ? how to change it to localhost ?

i'm not the one who setup this zcs that why i dont know

when i setup a fresh zcs, my "Web mail MTA Hostname" is always "localhost" and it works well

[phoenix]

Yes, you can change that to 'localhost' in the Admin UI page then hit save.