So you have a mailing list. You obtained genuine subscribers (yay for you!), or you decided to go find an easy way out and bought a mailing list for your email marketing activities. You feel confident that you can create great content for these people. You find a tool to build and deploy your email campaigns. You keep checking these analytics reports for opens and clicks. Time passes, and you still don’t get that engagement you were expecting.

Then you turn to Google and search for that missing link. You start to rethink your content strategy, maybe redesign your email template. But what about your mailing list?

missing link

The missing link: your mailing list

Good list hygiene is really important. Unfortunately, it’s also very much overlooked.

From my experience, one of the most difficult things psychologically in email marketing is letting go of your contacts. It goes both ways: persuade yourself or convince your broader marketing and sales teams.

Keep your mailing list clean

You keep hearing these phrases over and over again from best-practice advocates, various searches online, in many whitepapers, or discussions with others in the field: good list hygiene, clean up your mailing list, remove bad email addresses, and so on.

If you have the budget to do so you will probably go for data validation services that will verify your email addresses in your mailing list for you for a fee. These will surely help, but not all of us have the budget to do it periodically.



However, there are steps you can take to maintain a clean mailing list.

How to clean your mailing list for free?

Sounds like a good option straight away – but what does it really mean? Free does not mean easy. It will require you being on top of your game. So, what do you need to look at first?

What is deliverability?

Let’s start with start with deliverability. It’s a big word, but a necessary one to learn for all who use email marketing.  Deliverability is a topic for a long discussion, so I’ll just give you a brief introduction. You could define deliverability like this:

Deliverability is a measure of success of your emails reaching targeted inboxes – without bounces and abuse complaints (marking you as spam).

The higher the deliverability of your email, the cleaner your list is. You can calculate the deliverability ratio by using this formula:

emails received / emails sent = %.

Keep an eye on this one. Check your monthly deliverability scores, and you’ll eventually find out what your benchmark is and what your trends are. Then you can compare to your industry rates. If your score starts to drop, you will definitely know that you need to take action.

Some email service providers will show you your domain deliverability score – worth checking if yours can do that for you.




Email Bounces: hard and soft

The next thing that you need to check is your bounces.

What are email bounces?

Bounces are emails that do not reach your contact’s inbox and is returned to sender.

There are two main categories of bounces – a hard and a soft bounce.

  • Some of the reasons for a hard bounce are these: incorrect email addresses, not a valid domain, or recipient has blocked delivery of your emails (these sometimes are reported separately). Hard bounces should be suppressed straight away (and that’s usually done by your email service provider.
  • Soft bounce – these might be full inbox bounces, recipients’ server being down, your email not meeting their requirements (for example, too large), etc. Usually ESPs have a rule of 3-5 soft bounces, and after that they register that email as a hard bounce.



Here we are, the hardest thing of all – the sunset policy, or also called sunsetting and susnet provision. What is sunsetting?

Sunsetting is a process of suppressing your inactive contacts after a set period of time.

Data decays about 2% a month

This means that you should expect to see about 20-30% of your data go bad every year. One fifth or more of your list will get bad email addresses every year. That’s a scary number, isn’t it? And bad email addresses mean a big risk to your deliverability, including spam traps (read about them here).

Sunsetting is necessary – once your contacts become inactive for a long period of time, remove them from your live mailing lists. Don’t risk your overall deliverability.

Remember, the less engagement you have, the worse your domain reputation might get though the eyes of different ISPs.

We all have several companies that keep emailing you, you constantly see their emails popping up in your inbox, and they’re becoming quite annoying. You don’t engage with them, but for now you don’t have time or energy to go in and unsubscribe.

Some of us will just move them to a spam folder, but many of us will just leave these emails piling in your almost full inbox, or select and delete. And then suddenly you realise that you don’t see these emails popping up anymore. Maybe they finally got the point that you’re not interested, and stopped spamming you. And out of interest you check your junk folder which seems to have quite a few new emails. Voilà – they’re all in the spam folder. ISPs are smart like that – they do the job for you. If you don’t engage, or delete straight away without opening them, you’re telling the ISP that this is an unwanted email, and its place is in the spam folder.

You need to understand that you will not get bigger engagement or more sales from bulk sending your emails to everyone – it doesn’t work like that anymore. The more targeted your email lists, the better your engagement and your deliverability. And you can provide a more personalised experience.

Sunsetting works – I’ve seen open rates increasing by more than 180% after removing the non-engagers.

How to apply the sunset policy?

Put your emotions aside and follow these steps:

  1. Set a time frame for your non-engagers. Industry recommendation is 6 months.
  2. Once you have decided on the time frame it will mean that everyone who hasn’t opened your email within that period of time, will need to be suppressed from your live mailing lists.
  3. If you’re still not too happy about letting your email addresses go – create a good re-engagement campaign. If the non-engagers do not convert to engagers, it’s time to let them go.
  4. If you’re running many email marketing campaigns, and send different emails, you can be more creative. You can identify your non-engagers for different types of emails. Maybe one client will never open your newsletter, but will open a blog post notification. Create strong segments by analysing the performance of different categories – and use these for your emails. You will see an amazing difference.
  5. Various email sending providers will have different settings on how to apply this suppression technique to your mailing lists. Most likely it will be in a form of additional rules or filters to your existing queries.


Final word

According to a Securelist report, in Q1 2017, the percentage of spam in the overall email traffic amounted to 55.9%. And Return Path indicates that only 79% of commercial emails land in the inbox.

That means that 1 out of every 5 emails sent either gets filtered as spam or is blocked entirely. And they aren’t malicious emails; they’re (usually) legitimate, not-intended-to-be-spam emails. So I can’t stress enough, that a good list hygiene is one of the key aspects of successful email marketing.

As a fifth of the emails go to junk mail, you need put a lot of effort to get good inbox placement.

Do you want to risk your deliverability by bulk sending to all contacts? No you don’t.

I’ve created a Tailwind tribe dedicated for Internet Marketing, you’re welcome to join!


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