Email and DNS servers - how does it work?
July 27, 2011 3:10 AM Subscribe
I am in the process of changing my web hosting service. I have a bunch of questions about what's going to happen to my email.
This is a total n00b question so I apologise in advance.
I have just changed the DNS server settings for my website, let's call it www.binnight.com.au. No problems there, and within a day or three I guess my site will switch over to the new host.
My question is, what happens to my email in the meantime? Let's say I have rbn@binnight.com.au and it forwards to Gmail. I've set up my mail forwarding at my new host, so my mail should then be forwarded to my Gmail inbox, right? Once the new DNS server settings kick in, will my email also move to the new host? Or do I need to do something else?
If my email will move automatically, when will it move, and will any mails get lost in the meantime?
Again, sorry for my idiocy, I'm just trying to work out what will happen and Google only gives me answers which are far above or below my level of understanding.
Thanks!
This is a total n00b question so I apologise in advance.
I have just changed the DNS server settings for my website, let's call it www.binnight.com.au. No problems there, and within a day or three I guess my site will switch over to the new host.
My question is, what happens to my email in the meantime? Let's say I have rbn@binnight.com.au and it forwards to Gmail. I've set up my mail forwarding at my new host, so my mail should then be forwarded to my Gmail inbox, right? Once the new DNS server settings kick in, will my email also move to the new host? Or do I need to do something else?
If my email will move automatically, when will it move, and will any mails get lost in the meantime?
Again, sorry for my idiocy, I'm just trying to work out what will happen and Google only gives me answers which are far above or below my level of understanding.
Thanks!
During the transition period, some of your mail will still go to your old host (which will then forward it to gmail just as before). Mail from the parts of the Internet that have picked up the news about the DNS change will go to your new host. If you have that host configured to receive that mail and forward it to gmail too, then you won't even see a difference, it'll all just work.
posted by ook at 4:56 AM on July 27, 2011
posted by ook at 4:56 AM on July 27, 2011
If you have the account rbn set up at your new host in advance of the switch, then the worst that will happen, as Rhomboid said, is that a few e-mails will go astray to the old host for a brief period. If it's gmail-based, you should still have access to the old system using your username, right?
Otherwise, every e-mail should continue to get delivered either to your new host or your old one.
I try to do server transitions of this type on a Friday afternoon after working hours for this reason, but the likelihood is you'll lose little if any mail.
posted by randomkeystrike at 4:57 AM on July 27, 2011
Otherwise, every e-mail should continue to get delivered either to your new host or your old one.
I try to do server transitions of this type on a Friday afternoon after working hours for this reason, but the likelihood is you'll lose little if any mail.
posted by randomkeystrike at 4:57 AM on July 27, 2011
Keep in mind that many hosts (but still a minority) ignore TTL and cache longer than they "should" to save from having to do so many lookups on their end. Just google either "ignoring dns ttl" or "providers dns ttl ignored" or something and you'll read many stories.
With a few iptables rules (sorry, just know Linux, I'm sure there's Windows equivs) you can just take all incoming port 25 (and 80 and 110 and whatever other services you've got) and redirect to the new server while you wait for DNS to propogate.
posted by Brian Puccio at 5:31 AM on July 27, 2011
With a few iptables rules (sorry, just know Linux, I'm sure there's Windows equivs) you can just take all incoming port 25 (and 80 and 110 and whatever other services you've got) and redirect to the new server while you wait for DNS to propogate.
posted by Brian Puccio at 5:31 AM on July 27, 2011
I'm not sure whether you're asking this, but: existing messages stored on your old server will _not_ be on the new server, unless you've made a special arrangement with both hosting companies.
posted by amtho at 7:29 AM on July 27, 2011
posted by amtho at 7:29 AM on July 27, 2011
This thread is closed to new comments.
In the future, if you want to avoid this the way to do it is to preemptively lower the TTL value ahead of the move. For example, if it was set to 24 hours, then at some point greater than 24 hours before the move you should set it the TTL to something like 60 seconds. That way when it comes to actually do the move, you can be assured that all the caches that had the old 24 hour value have expired, and any caches now have the 60 second value. Now when you make the change, the period of time during which both records are valid will only last 60 seconds. After that, you can set it back to 24 (or 36, 48, whatever) hours to reduce traffic.
posted by Rhomboid at 4:47 AM on July 27, 2011 [2 favorites]