I don’t normally talk about industry averages because they rarely apply to any individual company within an industry, but for illustrative purposes here I’ll make an exception. The number most commonly offered up as an industry average open rate is 20%, and industry average click-through rates are typically reported between 2% and 4%. Your results may vary of course. But given these numbers, 80% of recipients on average do not open a message, and 96% – 98% do not click on any given message. Now some of these unresponsive people were responsive last week or last month, but it turns out that for many email marketers, a sizable percentage of the non-responders are chronic, and have not opened or clicked on a message for months or even years.

These are your inactive subscribers. You know them well enough to have them on your list, and they know you well enough to not unsubscribe. But for some reason or another, they’re just not that into you anymore. Some maybe never were, filtering your messages from the very outset into a folder that receives little attention, or even signing up with an email address they never check. Since the dawn of email until very recently, we had no real incentive to do anything special with these subscribers other than continue mailing to them hoping one day to get through. The cost of each subsequent message is very low (particularly compared to the upside from a click-through) and email success is a function of absolute activity, not relative. 200 click-throughs has always been worth more to your business than 175, even if you have to mail to 10,000 more people to get there.

The landscape has changed, however, and engagement metrics are now beginning to impact deliverability. What that means is that the unresponsive people on your list are making it harder to reach the responsive people. So it’s time to take a look at who these people are, and decide what you’re going to do about them, or else risking some downward pressure on your deliverability. There are three options to consider:

1. Remove inactives from your house file
2. Move inactives to a separate group for different treatment
3. Leave inactives in your house file and treat no differently

I’ll take a look at each and provide some context that might help you make a decision.

1. Remove inactives from your house file.
Taking the unresponsive people out of your house file altogether will result in an immediate lift on your engagement metrics. For example, if 5,000 people from your 20,000 name list has not opened a message in 13 months or more (the time frame I typically start with, since some responsiveness is geared around annual events such as membership renewals, annual conferences and holidays), simply omitting them from your next mailing can boost your open and click-through rates by 33%. If you’re at industry averages, your 20% open rate that drove 4,000 opens previously will still see the same 4,000 readers, but from the 15,000 people remaining on your list. You’ve climbed to 26.7%, sacrificing no absolute results and increasing the percentage of your recipients who interact with your message. This lift in engagement metrics signals to ISPs and email administrators that you’re a legitimate sender, decreasing the likelihood that your messages will be shuffled off to junk folders or bounced – a bona fide upside across your entire email program. The downside is that there is always the risk that you’ve assumed incorrectly – that someone who appears inactive is still seeing your messages in the inbox and waiting for the one that grabs her attention. The longer someone is inactive the less likely this is the case, but it is still something to factor into your decision.

2. Move inactives to a separate group for different treatment.
This approach mitigates the downside from option 1, in that you’re not cutting inactives loose entirely. Instead, you’re targeting them like you would any other segment of your list. Only instead of sending them messages based on what they have done or bought in the past, you’re sending them messages based on what they haven’t done. One approach is a dedicated win-back campaign, where you expressly point out that you haven’t heard from them and try to re-engage in some way. Another is pare down the frequency of the messages, only sending them the ones of the greatest strategic importance. These may be the announcement that registration for the big conference is now open, or changes in content or products or features that may appeal to them and shake them back into activity. Like any kind of targeting, this approach requires a little extra effort. But you will recognize the same lift in engagement metrics on the messages they don’t receive, which will still signal to ISPs that you’re on the level and your messages deserve to pass the velvet rope.

3. Leave inactives in the house file and treat no differently.
Technically, this is the “do nothing” approach and is a viable option based on your circumstances. If your deliverability and engagement metrics are already strong, despite a significant number of inactives in your list, maintaining your status quo could be justifiable. Remember that even unread messages carry a branding impact. If you do elect to leave your inactives in place, make sure that your subject lines still speak to them and work towards re-engaging them. Telegraph your message content so that even subscribers who only glance at their unread messages still feel like they’re in the loop with your brand.

An important consideration for any of these options is where your inactive subscribers came from in the first place. People who actively subscribed to your list or made a purchase showed a significant level of engagement at one point, and are more likely to be re-engaged in the future. But if your inactives are names acquired through a channel with low engagement (such as a list of trade show attendees you exhibited at, or a purchased list), the chance of them suddenly awakening to your brand after a year of ignoring it are slim. Better to cut them loose and lift your deliverability and engagement metrics.