The Case of the Missing AOL Mail Server: Four Steps for Marketers

Blame it on the first total lunar eclipse and winter solstice in 400 years, but AOL’s MX servers mysteriously went missing for approximately four hours after midnight. You’ve probably already read my colleague JD Falk’s article on this exact topic already which also provides a fantastic technical primer of MX records and how they operate. What this all means to you as the marketer or sender is that when attempting to deliver mail to an AOL address, your mail server couldn’t find the AOL mail server record, and potentially never successfully delivered mail to your recipients. An MX record is short for Mail eXchange record and it tells your mail server where to connect and send mail through in order to reach your intended recipients. However if an MX record is missing, the sending mail server will receive an error that says something to the effect of “sorry, I couldn’t find any host by that name” or “name or service not known.” In short, your mail couldn’t be delivered. In AOL’s case, the MX record was missing for almost 4 hours (12AM – 4AM EST) which means if you tried to deliver mail during that time to AOL, you weren’t able to. Here are four things to check:

1. Check your bounce report for AOL to see if you see any addresses were disabled due to an error like “host or server not found” on December 21st from 12AM to 4AM EST. If you don’t, you’re probably safe and it probably means that you weren’t sending any mail during the outage, and you can go to step #3. If you’re not sure what to even look for, ask your Return Path account manager or your ESP if you were affected. If you do see these errors, see #2.

2. Look again at your bounce report for any AOL addresses that may have become permanently disabled as a result of your bounce rules. Most mail servers will re-try sending until it reaches your re-try limit until it permanently disables the address, and some mail servers may immediately permanently disable addresses when a mail host isn’t found. You will need to re-enable these addresses in your database. Please only re-enable those that became disabled because of this error. Re-enabling addresses that bounced out because they returned an unknown user code (500, text= 5.1.1 : Recipient address rejected: should remain disabled.

3. Ask your mail server administrators to flush your local DNS to make sure that your DNS didn’t cache, or store, the wrong MX record, or lack thereof. If you don’t have your mail team look into this, it’s quite possible that you may still not be able to deliver to AOL until this is done.

4. You’re probably wondering if you should resend your mail campaign that didn’t get through. If you’re like most marketers, you’re probably sending last minute holiday emails. If the messages are timely and a re-send might result in your subscribers getting the email too late, and perhaps angering and frustrating them, use other marketing channels like Facebook or Twitter in hopes to reach your AOL audience, or look at offering your AOL segment a unique offer like free overnight shipping. If your offer isn’t time sensitive, feel free to send as normal.

While probably not the best timing for marketers with only 3 days left until Christmas, mistakes can and do happen, so it’s better to have a Plan B in instances like this, such as marketing to your other channels as noted above. I’ve also seen marketers ask for a backup email address to deliver things like transactional messages if their primary address becomes unreachable. Do you have a backup plan in cases like this? Please share!

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