In order to gain insight into the number of dormant contacts in your database, you must create a dynamic list in the Lists module. Go to the Lists module and click on the button New list.
In the first step you must name the list, for example: "Dormant contacts". In the second step, click on the Edit button to open the editor.
You will see the following screen:
On the left, click on +Selection. A pop-up will appear. Click on All contacts and then on OK.
Select the property Engagement: non-opens. Next, a pop-up will appear in which you can indicate the period selection of X number of months.
Make a choice depending on the frequency of your mailings. Do you send out a newsletter every month? Then you don't want your contacts to be inactive for more than 6 months. If you send a newsletter once every quarter, 12 months is a better option.
Please note: this feature is about opening email about all your email communication.
Next, click on OK. You will now have the opportunity to add more refinements.
It is only allowed to email contacts who have given permission. So, you'll want to exclude contacts who are 'dormant' because they haven't given permission for the newsletter.
Click on Add refinement to add the permission: Newsletter.
Your selection will look like this: