I just wanted to confirm something if that's okay? :) I am setting up a new site for someone and they already have email configured on an existing server and want the website on a different one. They have already set the www a record to the new server IP and this works fine and they have two MX records setup and the email is working fine. They have not updated the @ A Record, this is still pointing to the mail server IP (which means the non www version of the site goes there instead). Am i not right in thinking that if you have the MX records set then the A Records for both www and @ can be set to a different server IP and will have no impact on the email (as this will be controlled purely by the MX records)? So I can change the @ a record to the new server ip as well and this won't affect their email right? Assuming this is okay will it screw up the RDNS or any of the other email validation techniques?
Thanks so much for your help as ever,
Dave
You should be fine changing the root record. Whenever an email comes in it will always look at the MX records. There are two things to check though.
The MX records will point to a domain name, are they pointed at the root domain? Secondly do they use any form of webmail? You might need to create another record such as mail.example.com in order to ensure that they can still access these two things.
Most sender validation uses different DNS entries and doesn't rely on the A records in any way so you should be fine changing things.