Are dead email addresses haunting your open and click-through rates? If once-active recipients have stopped opening your emails, are no longer actively reading your messages, or aren't clicking on email links, those recipients are no longer in the land of the living.

In other words, if you're seeing low activity from recipients, it's time to determine whether the addresses can be saved or should be given the axe. In the spirit of Halloween, I offer some advice to determine whether your dying email list can be saved.

Are They Really Dead?

Many recipients have images turned off by default, so some recipients who are in fact reading your emails may only appear dead because the opens are not registered. To identify these recipients, start with a simple "reactivate yourself" message.

Select a group that has not opened a message in six months and send an email with this message: "To ensure you continue to receive our mailings, click here." The click verifies both the address and the recipients' interest. The click-through can take them to a special offer, or to a page where you might gather more information.

Saving the Undead

Try to revive dead email addresses. The first step is to identify the percentage of inactivity that is acceptable in terms of your marketing goals. Depending on your business model, someone who responds once a quarter may be good news. For other businesses, three months without an action could be the kiss of death.

Determine your average range of activity, and from there identify your low responders and non-responders. Your email service provider should be able to guide you on how to find these recipients in your list.

What Killed Them?

Once you've identified this group of recipients, analyze the data you have on them to look for any similar characteristics. For example, were these subscribers collected a specific number of months or years ago? Did they come from a certain acquisition source? Did they respond to a special offer that precipitated their signup?

Locating these similarities may help to explain their inactivity. It may also help you to brainstorm on how to revive them. For example, if someone opted in because of a great offer, perhaps it's time to re-engage them with another offer.

Finding the Elixir

Create a reactivation plan. The key is to start testing different approaches. Determine whether you want to treat low responders differently from non-responders. Decide whether you want to take a multi-email approach or a quick slash and grab.

One option is to send an email asking low and no responders whether they would like to continue to receive messages from you. If they still don't respond, you can comfortably call them dead and hack them from your list. Or consider offering them a particular benefit to come back to life, such as 20 percent off their next purchase.

Watching for Ghosts

Continue to watch your low and no responders carefully. One positive action alone may not indicate that they've fully crossed over to the land of the living. Determine at which point you can safely consider them revived and add them back to your active group. Until then, keep a close watch and consider altering your win-back approach if you're not seeing the results you expected.

Burying the Truly Dead

At some point you may have to accept that some of these addresses are truly dead and cannot be brought back to life. At that time, it's best to cut them from your list entirely. Better to focus your energy and resources on your active subscribers.

Getting Through the Mourning Process

Chopping off the dead weight from your list can be painful. No one likes to see a subscriber list decrease. Take this opportunity to learn from any mistakes. Perhaps it was an acquisition source gone wrong that you can avoid in the future. If you found it was older subscribers who were inactive, develop a lifeline strategy to deal with subscribers differently as they age.