Recover email lost due to improperly configured domain servers

November 10, 2006 11:49 AM

Email and domain administration help needed! I manage the domains for my parent's small business. Without thinking about what I was doing, I changed the domain servers listed at Domain Direct for my domain from 1and1 (my old web and mail host) to Dreamhost (my anticipated new west and mail host). The problem is, I hadn't actually signed up with Dreamhost at that point. So two days go by, and I just now realized my error. Of course, I immediately signed up with Dreamhost and set up the domain. My question is, can I do anything to recover the emails from the last two days? I've put my question into Dreamhost technical support, but in the meantime, I'd like to understand how this works technically, so that I can respond intelligently to the Dreamhost folks, and know whether what I'm asking for is even reasonable.

Thanks in advance for your help! This is kind of an emergency, as the emails I lost over the last two days may set my parent's business back several months, at the least.

posted by trystero to Computers & Internet (9 answers total)

Almost certainly not. Dreamhost's MX servers won't be setup to deal with mail to your domain, and will bounce it.
posted by Mwongozi at 12:05 PM on November 10, 2006

A few possibilities on what happened to the mail:

1. Dreamhost got DNS requests for your parents name and basically responded: I have no idea what you are talking about. In this case, the mail probably bounced back pretty much immediately to the original sender with a "host not found" error message.

2. Dreamhost got the DNS requests for you parents domain name and treated it as a parked domain and answered giving the information for their own mailservers. Their mailservers received the mail, realized it didn't match any of the addresses on their systems and sent an error message back to the sender.

In either scenario, it's possible that the senders e-mail filters treated the error messages as spam and they never saw them.

So, its quite possible that the e-mail senders got an error message, but it's also likely that they didn't, and so they think their e-mail went through.

You probably want to come up with a plan for communicating the problem to likely correspondents. Maybe an item on the home page of their website, a mention in any e-mail newsletter they send out, and an e-mail to anyone they were reasonably expecting to hear from during the outage period.

You have now learned the hard way that DNS screwups can be slow-motion disasters.
posted by Good Brain at 12:12 PM on November 10, 2006

99% no. Sorry. But not the way Mwongozi said; their DNS wouldn't have had an authoritative record for you so the traffic would've gotten bounced back to the sender.

Technical reasons:

There's two records at work here.
1) Domain Name - Your domain name is pointed at a few DNS servers, which you already know. Those DNS servers are considered to be 'authoritative' for the domain.
2) DNS - The 'authoritative' servers are checked to see if they know what server to direct traffic to. If they don't (and this is where your chain breaks, because Dreamhost's DNS servers would NOT have an authoritative record for your parents' domain) ... the traffic either gets blackholed or it bounces back to the sender.
3) DNS's MX record - If there is an authoritative DNS record, this line in it tells the email which specific server (IP address) to go to.

If your parents' business is dependent on having solid, steady system admininstration in place, no offense, but they should really consider having a professional administer their domains and servers. Shared hosting is nefariously buggy, and they will lose emails anyway due to other people doing bad things on the shared server and the unreliabile nature of servers where many, many people are hosted.
posted by SpecialK at 12:13 PM on November 10, 2006

Best answer: I did a quick test. I issued an MX query to ns1.dreamhost.com for a domain that exists, but is not hosted by Dreamhost. The DNS server returned SERVFAIL. This indicates a "failure to resolve." If it had returned a result of NXDOMAIN/empty it would have been saying "I affirmatively deny the existence of the requested mail server."

In the case of mail from your parent's clients, your client's outgoing most mail servers will most likely treat a response of SERVFAIL the same as if a domain's DNS server was down. In this situation most mail servers will queue the mail and periodically reattempt delivery. The time that mail will sit in mail server's queue before being bounced varies depending on mail server software and configuration options, but it usually is three to seven days. In my opinion, there is a good chance that most of the mail that could not be delivered in the last two days will appear in your parents inbox within 24-48 hours of you getting the DNS correct.
posted by RichardP at 12:19 PM on November 10, 2006

Best answer: Actually, Dreamhost is returning SERVFAIL for requests for domains that it doesn't own. Most MTAs will follow retry procedures on SERVFAIL, only bouncing after several days of failed attempts.

So these messages should be coming in to you over the next day or two. There is nothing you or Dreamhost can do other than correctly setting everything up; the actual delivery has to be retried by the sending MTA.

% dig @ns1.dreamhost.com nonexistantdomain23984.com MX

; <>> DiG 9.2.2 <>> @ns1.dreamhost.com nonexistantdomain23984.com MX
;; global options: printcmd
;; Got answer:
;; ->>HEADER< - opcode: query, status: servfail, id: 47386br> ;; flags: qr rd; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;nonexistantdomain23984.com. IN MX

;; Query time: 69 msec
;; SERVER: 66.33.206.206#53(ns1.dreamhost.com)
;; WHEN: Fri Nov 10 12:16:11 2006
;; MSG SIZE rcvd: 44

posted by trevyn at 12:21 PM on November 10, 2006

Oop, props to RichardP.
posted by trevyn at 12:21 PM on November 10, 2006

Hmn, yeah, props to RichardP. I configure my DNS servers to return NXDOMAIN, so I didn't realize that Dreamhost would return SERVFAIL -- that's a *much* smarter response to issue. I wish I could get hosts to return SERVFAIL for me when I'm switching DNS away from them as things propagate. ;)
posted by SpecialK at 12:37 PM on November 10, 2006

Response by poster: Thanks, RichardP and trevyn! That is fantastic news. I really appreciate the help.

If your parents' business is dependent on having solid, steady system admininstration in place, no offense, but they should really consider having a professional administer their domains and servers. Shared hosting is nefariously buggy, and they will lose emails anyway due to other people doing bad things on the shared server and the unreliabile nature of servers where many, many people are hosted.

SpecialK: I agree. My parent's business is in the startup phase at the moment, so they can't afford much, but I will continue to push for that to happen as soon as possible.
posted by trystero at 12:53 PM on November 10, 2006

BTW, I think it's completely practical to have reliable e-mail with shared hosting, but not via dreamhost & 1&1 tier companies. Look for someone who specializes in e-mail hosting.
posted by Good Brain at 3:44 PM on November 10, 2006