If you’ve been in the business of email marketing for a while, it’s likely that you have collected quite a large number of email addresses. You probably have a group that are [hopefully] engaged with you and open and click your emails frequently. Then there is the rest of your list…one group that is unengaged and hasn’t interacted with your emails in quite some time. These might be marked as unmailable due to hard and soft bounces and unsubscribes. Since the inactives and unmailables are probably a majority of your email list, take some steps to clean them up or remove them from your mailing stream. In the end, you may experience an increase in email metrics along with better inbox delivery.
First, take a look at some of your email metrics to determine how customers are reacting to your email campaigns. The failure rate is an important number to watch because it shows how many emails never made it to the customers in your email list. Failures can include hard bounces, soft bounces, connection errors and other technical issues that made your email undeliverable. You should be sure to take action and remove any hard bounces from your email list, since the address is no longer valid and can only further harm your deliverability.
Some other important email campaign statistics are the unsubscribe and complaint rates. These rates indicate how your customers are responding to your email. If subscribers don’t see value in receiving your emails, they are going to take an action of either unsubscribing or complaining (marking your email as spam). While neither of these actions are desirable, it is better to have customers unsubscribe since this action goes under the radar of ISPs. A complaint will notify the ISP that a subscriber believes your message is spam. If too many people complain about your email, it’s likely that all of your incoming mail will be blocked or immediately sent to the spam folder. If you have feedback loops in place, you will be notified of which subscribers are complaining and you can immediately remove them from your email list. According to CAN-SPAM regulations, you legally have 10 days to remove an email address from your database. However, it’s in your best interest to remove any addresses that unsubscribe or complain immediately to avoid any extra harmful behavior.
The churn rate is another metric you should be monitoring. Depending on how often you mail, you might report on this metric differently, but calculate it by month to see how you trend throughout the year. You simply need to add the total number of unsubscribes, complaints and unmailable addresses and divide by how many total email addresses you have at a certain point in time. This will give you a percentage that indicates how many email addresses you lose each month. If you have email acquisition efforts running, this number is important since you pay for every email address you acquire and should have an idea of how many you will lose due to churn.
Next, take a look at the composition of engaged and unengaged users in your email list. Instead of continually emailing to everyone in your list, find those that are most engaged and target them for your campaigns. To find these customers, run counts of users in your list that have recently taken an action on your email. Depending on how often you send email campaigns, try running counts of those that have opened or clicked on an email in the past three, six, nine or twelve months. And depending how quickly you acquire new subscribers to your email list, run counts of users who have recently been added to your list in the past week, month or quarter.
Then you will need to put together a testing strategy where you mail these groups separately and track how each responds to your email campaign. From here you can create separate lists of the most engaged users that will optimize your email campaigns. Not only will you experience better email statistics – ex. open and click rates – but you are likely to have lower unsubscribe rates and fewer delivery issues. If you do experience deliverability issues, it might be a good idea to separate your database into separate engagement lists. First deploy your email campaigns to actively engaged users, then roll it out to the moderately engaged (and possibly then unengaged). This strategy will allow your email to be immediately opened and clicked and will indicate to the ISPs that it is a message of value and should be delivered to the remainder of users.
For those in your email list that are dormant engagers or completely unengaged, you may choose to either mail them less often or not at all. Put together a separate email strategy for these users that gives them the opportunity to re-engage with your brand or to opt out of receiving emails. Since these subscribers haven’t engaged with you recently (or ever), it’s likely that they won’t respond and you’ll have to decide what action to take for them. If this is the case, your best bet would be to put them on the back burner and email them quarterly with the options above.
If you have a large email list, you’ve probably collected a very large amount of invalid email addresses. This group could hold a trove of valuable customers, but for some reason, they are not able to get your email due to typos, fat-fingering, their mailbox was full, etc. Whatever the reason is that they were marked as invalid, there are some options available for recovering these email addresses. There are several third party companies in the market that can help with your recovery efforts. Many will provide free or reduced-fee trials to help you decide which of their services will best hygiene your list.
One service that is offered is an email syntax check. They will take your entire list of invalid email addresses and check each one for common mistakes and errors that would cause your email to be unmailable. Such things as misspelling a Yahoo address as ‘@yahho’ or missing the shift button and typing a 2 instead of an @ sign could cause an otherwise correct email to bounce. You would then be returned a list of corrected email addresses that you can now try to re-mail. Be careful when mailing these recovered email addresses though. Remember they have probably never gotten an email from you and it may have been awhile since they signed up for your email list, so the first message you send them should be some form of welcome email.
Another service offered by third party hygiene companies is a validation tool. This software is designed to catch syntax and spelling errors up front, and ensure that the hard bounce never happens. This service happens at the time when the user enters their email address. Once they hit submit, the service will verify that the email address is both properly formatted, as well as checking it for common errors and typos. If it detects an issue, it will provide several options of what it ‘thought’ the user was trying to enter and force the user to choose the correct address. Although pricey, this service can do wonders in preventing bad email addresses from entering your database.
In all, there are many different ways to hygiene your database. It is important to constantly keep a clean mailing stream as ISPs get stricter and stricter with delivery standards. Whatever budget and resources you have available, it can only benefit you and your bottom line to ensure that you are only mailing those in your email list that want to be mailed.



