DNS Propagation questions for the internet gods

[eisenhard]

I have a basic understanding of how propagation works. I have a site on hosting company A and want to move it to B. So I set up an account on B, copy over the files & set up the email addresses.

Then I go to the registrar for that domain and change the nameservers from A to B. Then I wait. Most of the time I can ping the domain name within 2 hours and have it resolve to an IP for hosting company B.

Currently I am in a situation where I did this last night at 7pm. Today at 4pm the web site has resolved but the email is not. At least I get an error every time I try to send an email to an existing address on B.

I understand that many ISP's cache the DNS. So this leads me to question #1...If the "place" that is attempting to deliver me email has not updated its cache then why would it not attempt to deliver that email to the old server IP...which is still setup and capable of receiving email?

My second question...How can I go to several sites that give me DNS resolution info for a given domain and have them ALL resolve to the new hosting company server IP but the email will still not be delivered?

Why do companies not update their DNS cache more frequently?...like every 2-4 hours. I would think this could be an automated process. It seems unreasonable that I have to explain to a good customer of mine that relies on email every day to do business that they will just have to go without it for a couple of days.

Thank you to the internet gods (or anyone else) for any answers they can provide.

[Romeo]

Welcome to W.W.

The time how long an ISP user's local DNS server somewhere in the world whould cache DNS records of your domain is individually set for your domain by the TTL value within your own domain's zone file. This is often set to 1d (1 day) or more.

So, before switching to another host, you should have reduced this value (perhaps to 1h), forcing caches to be refreshed more often, and to restore that TTL to old levels again after your situation will be stable again after a few days.
If you have full control over your zone files, though. If you don't host your DNS on your own, many shared web hosters won't let you fiddle with these values.

I don't have an answer for your mail problem. Perhaps it is not a DNS problem but the mail stuff on the new location is broken? Or the local mail client config needs an update on some parameters (pop3? imap? plain text? encyrpted? user/passwords? smtp auth?)? Or I didn't fully understand your problem at all ... sorry.

Kind regards,
R.

[eisenhard]

Thank you for your post. I did not know the TTL was something I could change. Where would I edit that value for a domain? Would that be done at the registrar (if yes, what section is it commonly found under?). Thanks in advance. :)

Here is the end result of my issues and how they were resolved...

Here was my last Support Ticket to the Hosting Company:

"I do not believe this is a propogation issue. The web site propagated within 2 hours last night. Here is the error message I receive when trying to send an email to <snip>.

"Your message cannot be delivered to the following recipients:

Recipient address: <snip>

Reason: Remote SMTP server has rejected address

Diagnostic code: smtp;550-vms044pub.verizon.net [206.46.252.44]:33972 is currently not permitted to relay through this server. Perhaps you have not logged into the pop/imap server in the last 30 minutes or do not have SMTP Authenticat

Remote system: <snip>

The fact that I can ping <snip> and hit a HostGator IP and the HostGator mailserver & IP are mentioned above in the email error message lead me to think the email was properly directed to the HostGator mailserver but rejected for some other reason.

Please look at this also: <snip>

The report on this site shows that when pinging <snip> the HostGator mailserver (batmobile.websitewelcome.com) is found and hit but it seems to have 2 responses called "Administrative prohibition" which look suspicious.

If this is not fixed by tomorrow morning we are going to lose a very important client and HostGator will have lost our respect as the best hosting company we work with.

Please look into this further ASAP.

And here was their response:
<snip> was setup in the servers remotedomains setting and needed to be moved to the localdomains so that mail can be accepted at the server here.

And then the issue was fixed.

This sites results is what made me force the issue with them that it was not a propagation issue: <snip>

[edited by: lawman at 10:25 pm (utc) on Feb. 28, 2008]

[Romeo]

Just a side note: you probably should edit out your sitespecific data in your posting above, before a moderator is seeing it, as it is against the W.W. TOS to spread such things. We all have just one common domain here, all have the same, that is 'example.com'. :-)

Where would I edit that value for a domain? Would that be done at the registrar (if yes, what section is it commonly found under?).

Basically, at the point where your DNS zones are hosted (who provides the name servers). It could be your registrar, it could be somewhere else, perhaps (most likely) your site hoster (if they are not the same, as you mentioned Verizon).
But as I said in my earlier posting, perhaps they won't let their customers fiddle around with these values, which may be the main reason that you haven't found it yet (and would never find).

Glad that your mail problem cleared, and as I assumed, it was not a DNS problem but a config problem somewhere, as their error message suggested.

Kind regards,
R.

[eisenhard]

Romeo,
I could not edit my post so have asked a moderator to help me with that.

Thanks for all you help nad useful information!

[lawman]

Edit done eisenhard. :)