Is MX Guarddog down, and what’s the safest way to bypass the outage?
Asked by
MellowPine47
I noticed this morning that no mail had arrived since around 5 AM Pacific, so I checked MX Guarddog's site and found a major outage notice. Their Phoenix colocation facility reportedly lost cooling, then lost connectivity, and there is no clear estimate for full recovery. They recommend that customers who can do so temporarily change their MX records to point directly to their own mail servers. Is anyone else affected, and are there any gotchas when switching over?
Answers
If you bypass the gateway, first confirm that your mail server accepts connections from the entire internet. Some environments only allow inbound traffic from the filtering provider’s IP ranges. You’ll also need to account for the sudden increase in spam and phishing, review SPF and DMARC behavior, and document any firewall or connector changes so they can be reversed later.
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We had to redirect several domains directly to our mail servers. The change worked, but DNS propagation was not immediate, and some senders continued retrying the unavailable gateway. Anyone making the switch should monitor inbound mail closely and be prepared for more junk mail while filtering is bypassed.
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This highlights why an email-filtering service needs genuine geographic and infrastructure redundancy. Having multiple MX records does not help much if they all depend on the same facility. Most senders will queue and retry for hours or even days, so delayed mail is more likely than permanently lost mail.
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The outage appears to be a single-site failure rather than just a temporary mail-routing problem. A cooling failure can take down equipment regardless of whether the site is in Phoenix or somewhere colder; the important issue is that there was no effective failover to another location. I’d be reviewing any provider’s actual data-center redundancy claims before continuing to rely on them.
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QuietMarble6: It’s also worth lowering the MX record TTL before switching back. Keep the direct and filtered paths available for a while because DNS caches will continue sending some traffic to the old destination.