Pruning HAMY email addresses

Contrary to logical thinking, it may be beneficial to eliminate certain email addresses from a carefully cultivated address list. Much like pruning branches on a vine, culling certain email addresses from an email marketing list may bring forth more fruit and improve the overall health of the plant.

The addresses in question are Hotmail, AOL, MSN, and Yahoo! (HAMY). (Other addresses could be added to this list, like BellSouth, but it doesn't make a very effective acronym.) The main purposes for weeding out these types of inactive addresses from the list are to preserve the rest of the list, maintain a good email reputation, and decrease chances of being blacklisted.

HAMY behavior

A HAMY type email behaves in specific ways that can bog down deliverability. Many of these ISPs deliberately make senders hit all of their mx (mail exchanges) before they accept a message. In some of the troubleshooting I have performed, I have seen Yahoo! and Hotmail addresses ping up to five mx records before the email was finally accepted. While each ping may only be a few milliseconds, when sending thousands of emails to these email addresses it adds up and clogs the campaign.

Hotmail (officially Windows Live Hotmail now) also limits deliverability for new email marketers. If a new IP starts sending email to some undisclosed number of Hotmail email addresses, it limits the number of emails it accepts. When this occurs, they typically do not bounce them (send an error message), they simply ignore them and let them drift in the dark matter of the Internet. There is no way to know if these email messages ever reached their intended destination.

Once a sender establishes a good track record by successfully sending some number of email messages (again, undisclosed) they are bumped up to the next level and can send more email messages. Once at this level, however, email senders are not out of the woods yet. This stair step approval process may go through several iterations before sending to Hotmail. Emailers must evaluate their goals to determine whether these addresses are even worth the trouble.

Why HAMYs are worth less

I did not say worthless, but specifically mean worth less as they relate to other email addresses from other web domains. Most people who browse and shop online maintain two or more email addresses; one or more may be a throwaway address. These throwaway addresses are typically freely available from Hotmail, AOL, MSN, and Yahoo! Nobody wants to waste resources on setting up a throwaway email address on their domain, so they get a free account.

Using myself as an example, I can say I use accounts like this for this very purpose. If I am interested in receiving information from a website that is pertinent to work, I use my company email address. That way I can be informed of news and trends that will help me do my job better. If I am at a website where I don't know exactly what to expect in regards to their email practices, I use my throwaway account. I check this account to look at the immediately requested information, but once that is retrieved, I just let whatever else comes in sit there and build up (recently defined as BACN, as opposed to SPAM). Gmail is great for this since they allow so much storage, but I wouldn't lump Gmail in with the HAMY types just yet.

Extrapolating this type of behavior to even a small percentage of online email users make these types of email accounts worth less than email addresses with a variegated domain identity. It is not to say that all of these types of email addresses are bad, or are used in this way, but since so many are, it may behoove the email marketer to simply ignore these addresses when they arrive in their list.

Another option, if deleting them is totally out of the question, is to segment them from a high performance production list, and send separate email message to the HAMY types. These could be sent at a slower pace, less frequently with more activity monitoring. As soon as open rates and click through tracking cease for one of these addresses, it is time to eliminate it altogether.

One final thought on the value of HAMY addresses is the level of experience for most users. During the rise of the Internet, when free email was all the rage, novice users flocked to these accounts in droves, and I suspect are still the main purveyors. As such, their email accounts are full of spam and forwarded links and they don't even realize it doesn't need to be that way. These types of people might not be spending any money, or really be interested in any messages other than from family and friends, and friends of friends, etc.

Free up the potential of an email marketing list by eliminating the deadweight. The SMTP server will perform better, email reputation will increase, and delivery will improve. – Arial Software

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