Hi, Here i am having two exchange servers in two diffrent forest as ABC.com and XYZ.com in lab Environment Lab setup: ABC.com DC --> DC.ABC.COM EXCH-->EXCH.ABC.COM IP Address Setup : 10.1.1.10 , 10.1.1.11 XYZ.com DC1--> DC1.XYZ.com EXCH1-->EXCH1.XYZ.com IP Address Setup : 10.1.1.20 , 10.1.1.21 Created DNS Forwarders, Where i am able send and recive mails with smart host Smtp Connecter, Where i am able to drop mail through Telnet as well, But unable to send and receive mails using MX record in lab setup Set q=mx results from XYZ.com (From Exchange 2003) ABC.com primary name server = DC.ABC.com responsible mail addr = hostmaster serial = 3 refresh = 900 (15 mins) retry = 600 (10 mins) expire = 86400 (1 day) default TTL = 3600 (1 hour) Set q=mx results from ABC.com XYZ.com primary name server = DC1.XYZ.com responsible mail addr = hostmaster serial = 3 refresh = 900 (15 mins) retry = 600 (10 mins) expire = 86400 (1 day) default TTL = 3600 (1 hour) Is there any can help me out to resolve this particular issue, i am not sure that is that DNS issue or Exchange Issue

Run this on server EXCH1.xyz.com: NSLOOKUP SET TYPE=MX abc.com Run this on server EXCH1.abc.com: NSLOOKUP SET TYPE=MX xyz.com Also please post your SMTP Connector configuration on each server, especially the settings for Address Space and Smart Host. Ed Crowley MVP "There are seldom good technological solutions to behavioral problems."

i think both the commands are same where as set q=mx and set type=mx but i ran the commands here the results set type=mx results from XYZ.com (From Exchange 2003) ABC.com primary name server = DC.ABC.com responsible mail addr = hostmaster serial = 3 refresh = 900 (15 mins) retry = 600 (10 mins) expire = 86400 (1 day) default TTL = 3600 (1 hour) set type=mx results from ABC.com XYZ.com primary name server = DC1.XYZ.com responsible mail addr = hostmaster serial = 3 refresh = 900 (15 mins) retry = 600 (10 mins) expire = 86400 (1 day) default TTL = 3600 (1 hour) And Address Space : * Cost : 100 Smart Host : if i add Smart host entry as (FQDN or IP Address) of the destination forest exchange server from the source forest Exchange server, vice versa on the other forest --> mail flow working as i tested earlier with smart host, because if we use smart host its like mail will dropped to remote host where the recipient can resolved on the remote forest mail will be dropped to the Remote server mailbox --> From Exchange point everything fine in SMTP Conncter or SMTP Virtual server like Authentication evrything seems to fine --> using MX record i am not able to send mails to the other forest,

That doesn't look like what I get when I run NSLOOKUP. C:\>nslookup Default Server: UnKnown Address: 10.0.0.1 > set type=MX > microsoft.com Server: UnKnown Address: 10.0.0.1 Non-authoritative answer: microsoft.com MX preference = 10, mail exchanger = mail.messaging.microsoft.com > quit So will you please do as I asked and run NSLOOKUP? If you want to use the smart host method, which is probably better than the MX record method in your case follow this procedure: On server EXCH1.xyz.com create a new SMTP connector with address space abc.com, and smart host of the FQDN or IP address of server EXCH1.abc.com. On server EXCH1.abc.com create a new SMTP connector with address space xyz.com, and smart host of the FQDN or IP address of server EXCH1.xyz.com. Ed Crowley MVP "There are seldom good technological solutions to behavioral problems."

yes i has tried this smart host method earlier, mail flow works fine. but i trying to figure it out the DNS issue i tried this command externally as you said , i get the same result Non-authoritative answer: microsoft.com MX preference = 10, mail exchanger = mail.messaging.microsoft.com but internal in lab a Environment , i am not getting the same. so i am trying to figure it out what may be the problem with DNS

Try the commands I originally gave you. Run this on server EXCH1.xyz.com: NSLOOKUP SET TYPE=MX abc.com Run this on server EXCH1.abc.com: NSLOOKUP SET TYPE=MX xyz.com This will tell you what host is being returned for the MX record. The output you provied before did not.Ed Crowley MVP "There are seldom good technological solutions to behavioral problems."

Hello Ed , Thanks for your help, here i resolved the problem by adding a DNS server in b/w two forest ABC.com DC --> DC.ABC.COM EXCH-->EXCH.ABC.COM IP Address Setup : 10.1.1.10 , 10.1.1.11 Default Gateway : 10.1.1.1 ------------------------------------------ DNS server : 10.1.1.1 created Forword lookup Zone as : COM created Host A : ABC pointed to 10.1.1.11 Created Host A : xyz pointed to 10.1.1.21 MX records created MX records pointed it to respective host records ------------------------------------------ XYZ.com DC1--> DC1.XYZ.com EXCH1-->EXCH1.XYZ.com IP Address Setup : 10.1.1.20 , 10.1.1.21 Default Gateway : 10.1.1.1 Exchange settings remains the same as smtp connecter is routing the mails through MX record And thanks for your help ED,