Your subscriber list, the unsung hero of your email marketing, can easily be “set and forgot” while the more exciting creative front end receives attention.

However, to do so would be neglecting the backbone to your email marketing performance. A well-maintained database will deliver far better results in the long-term (and require fewer emergency interventions along the way); to give your data some ongoing attention is time well spent.

Here are some health checks to keep an eye on, plus the steps to take when there is cause for concern.

(Note: most of these could also have other, front end causes. Here we’re focusing on the data explanations)

Open rate

There are two data-related reasons why this figure could be going down.

The first could be attributed to an unengaged list of subscribers. People change jobs (and email addresses) all the time, and an unchecked inbox does not open emails. Sometimes this will cause bounces, which a platform like the Salesforce Marketing Cloud will eventually catch and hold the email address. However, in many instances, (especially if the address is not associated with a corporate account), ISPs will repurpose the address as a spam trap.

Which brings us to the next reason: bad deliverability. If an email list is in extremely poor health, the sender’s reputation can be adversely affected: meaning more emails in the spam folder, or worse, blocked entirely.

Performing regular email list cleanses will help both the above issues. Run a query on how many subscribers haven’t opened or clicked within a period (six months is recommended if this is the first time), and send a reactivation campaign to this group. If there is no response, it’s time to remove these email addresses from the database.

Click through rate

When subscribers are opening, but not clicking, it’s a sign that what is being sent may lack relevance and further segmentation is needed.

If more subscriber data is available, it would be wise to put it to use. If an attribute (e.g. state or gender) is required but unknown, an update details campaign may be in order.

Regardless of whether there are new attributes, sending an update details campaign to subscribers once a year is good practice since these keep database information as accurate as possible.

Another solution may lie in offering subscribers more options in their preference centre around the content they receive (e.g. sale alerts vs. newsletters, or attributes such as male/female/kids department clothing). Appending this to their profile will mean they only receive the content they have asked for (and are more likely to click on).

Unsubscribe rate

If email unsubscribe rates are consistently above your industry’s benchmark average the data source could be to blame.

Are people being opted in without consent (and no, a purchase is not consent)? Has a database shared from a partner not been properly on-boarded? Are you not being clear what they are opting in to?

All these can mean a subscriber will be surprised (or annoyed) by receiving your emails, and at best they will unsubscribe and at worst will report the send as spam.

Set subscriber expectations early (on the sign-up form, or in an introductory email) and be careful to wash and get consent from any new database contacts.

By keeping an eye on overall metrics, and performing maintenance campaigns such as reactivation and update details, your database should remain healthy. It is the active subscribers who matter, not the overall database size.