Question about Mail Exchanger entries

[Genx87]

We are in the process of testing exchange with the expectation of moving it back in house. And one question I have is if we were to register a domain name with the name of mail.ourcompany.com and added it to our mail ex list with a low priority. If we created a recipient policy to capture email with our domain name will this work without disrupting flow of traffic to our offsite provider? My understanding of how mail ex work is the smtp server will query your dns server and look for a mail exchanger entry. It will run through the list contacting each mail server by priority until one responds with a positive match?

Ill be creating a test account so the email wont match any email address's we have at our offsite provider.

 

[netsysadmin]

First thing is when you say register mail.ourcompany.com do you mean with your DNS server that the third party sompany is running or are you trying to register a new domain name? If you mean registering a new domain you cant do that. sub domains get added under you existing domain on the DNS server that holds you DNS records.

Second thing is is you create priorities with you MX records you would have to have the whole mail server that is run by the other company taken offline before mail will go to your exchage server that you are testing. Priority is not based on email accounts that it can or cannot locate it is only based on whether the email server is responding or not.

John