Silvestras5 min readTips & ResourcesFebruary 10, 2016

Subscriber list quality control – why is it important?

Subscriber list quality control – why is it important?

Maintaining a quality list is often an overlooked part of email marketing. Quality means subscribers that open and read your email. Ideally they follow it up by clicking on your links, visiting your website, buying a product. Even if you have extremely engaged subscribers – over time your list will need some maintenance.

In this blog post we will advise you on a proper list hygiene and how it can help you increase your open rates.

Quality over quantity

Assuming you have collected your subscribers in a proper fashion, you have a good quality list. However, your efforts should not end here. Maintaining the quality should be as much important as collecting new subscribers.

As with many things in life, quality is usually preferred over quantity. Same goes for subscribers – it’s more profitable to have 20,000 subscribers with a 30% open rate than 100,000 subscribers with a 3% open rate.

With that said, even the best list will lose its value over time. Some subscribers will bounce, some will unsubscribe and some might even mark your campaigns as spam.

While MailerLite does the work for you and stops sending campaigns to such subscribers, it is your responsibility to take care of the rest. Let’s find out some important points of do’s and don’ts.

#1. Validate your list

First of all, if you haven’t sent campaigns to your list for more than a year – you will have to do some cleaning. This is important, because subscribers that deactivate or abandon their inbox may become spam traps. Sending a campaign to a spam trap will result in significant decrease of your sender reputation and future campaigns will land to junk folder.

Good news – there are various email validation tools online. The one we recommend as a very reliable is called BriteVerify.

If you have uploaded your list from another ESP – make sure bounced emails are removed. If your ESP does not provide the option to export only active subscribers – you will have to validate all imported emails.

#2. Let them unsubscribe if they want to

I have talked about the importance of unsubscribe link before, but it’s worth mentioning again. Make sure the unsubscribe link is visible in the footer section of your newsletter.

It’s better not to cling on your subscribers and let them unsubscribe if they want to – hiding the option to do so can backfire in a form of a spam complaint or even a SPAMCOP report.

Read more on how to use our Unsubscribe page to try winning back your unhappy subscribers.

#3. Dealing with inactive subscribers

Inactive subscribers are those that don’t open your letters, don’t click on anything and don’t show any signs of life. Email marketing experts have inconsistent opinions about whether you should keep such subscribers or remove them completely.

From an economic point of view, keeping such inactive addresses in your list may become pointless – they only increase your list size without contributing to any potential gain. On the contrary, they can even do some damage to your sender reputation.

Recent HubSpot’s experiment showed that email deliverability is affected by engagement metric. High number of inactive subscribers means lower open rate. And low open rate can result in ISPs treating you as a potential spammer. Removing inactive subscribers will technically result in higher open rates and better sender reputation.

On the other hand, some email marketing gurus like Dela Quist from Alchemy Worx believes that it’s better to keep those inactive subscribers. He argues that you should continue sending them campaigns and eventually it will result in an open or even a purchase.

#4. Send a win-back campaign using the new Reconfirmation template

Following up on the last paragraph, we believe it’s a good idea to send a reconfirmation or a win-back campaign to your inactive subscribers. Such campaign will clarify whether those subscribers are really “dead” or just pretending.

For this purpose, our designers have created a dedicated “Reconfirmation”template. The main idea of this template is to get a feedback from your subscriber.

Important note: when you send the reconfirmation campaign – give it a couple of days for your inactive subscribers and then act on it. If they did not reconfirm – it’s better to change their status to unsubscribed instead of deleting them completely. If they reacted – you can continue sending them regular campaigns.

You can also use the reconfirmation campaign to reengage with your subscribers. For various reasons, there might come a period when you stop sending campaigns. It is recommended to send a reconfirmation email to subscribers that haven’t heard from you for more than a year.


To sum up, subscriber list quality is the keystone of a successful email marketer. If you are sending to a list full of invalid addresses, spam traps and inactive or unengaged subscribers – even the best newsletter content or sender reputation will not help you.

Use the tips mentioned in this blog post and you will have a high quality list of engaged subscribers and potential customers.