I asked this question before, which was answered well, but I had some additional questions, so thought to ask a new questions.
My domain is kam.com, MX = mail.kam.com
There is a sister company (completely seperate) - sister.com, MX = mail.sister.com.
Sister has a website, www.sister.com
, and an A record for this;
sister = 184.108.40.206
The current TTL for Sister's resouce records is 24 hours.
Ours and our sister company's IT will be integrated, so that their mail will go via our mail servers. We will also take ownership of their domain completely, however the website should remain as is. There should be minimal downtime for mail whilst the MX records propogate round the world.
a) For the domain ownership, would I be correct in thinking that each domain on the Internet has a registrant who registers the domain on behalf of the Internet Naming org (not sure of the name?!). How would we actually take ownership of the domain?
b) Does taking ownership of the domain relate to making our public DNS servers the authorative servers for the sister.com domain, or is it a completely seperate task? Out of interest, is it possible for our servers to be authorative for the domain, but the domain to be still owned by a seperate org/held by seperate ISP?
b) For the mail routing change, their MX needs to be changed to mail.kam.com, but to minimise the time taken for the change to be made, should be amend the TTL of the resource records a couple of days before the change? That way all the DNS servers around the world would update their caches quicker?
c) Should we take ownership of the domain *before* the MX change, after the MX change, or does it not matter?
d) In order to keep the A record for www.sister.com
as it is, is there anything special we need to do?
Many thanks in advance! It's the first time I'm doing this, so just want to make sure I get it correct!