Sometimes, you just want to make sure that some of the contacts won't receive your emails. They may be either from your external database where they've unsubscribed earlier or were blocked for any other reason. If you keep them in a separate list, this list is called a "suppression list" or a "blocked contacts list". Below are two methods for how such lists can be managed in Elastic Email.

When you upload new contacts in Elastic Email dashboard (to any list), you will find a "Set uploaded contacts status to" option - from the dropdown menu select "unsubscribed".

While "unsubscribed" contact is still part of the sending list and counts towards the number of sent emails, it will automatically be suppressed and will not receive any message.

When you create a segment (dynamic contact list), it will contain only those contacts that match a specific rule. In order for it to work, you need to create at least two static lists: one with your normal contacts (let's name it "TheOKlist") and one with the contacts you want to suppress ("TheNOlist").

Now, create a segment (let's name it "TheFINALlist" with the following rule:

From now on, whenever you send to "TheFINALlist", it will include contacts from "TheOKlist", but will automatically exclude the ones that are on "TheNOlist".
This method ensures that there will be no attempt to send to the blocked contact, resulting in a smaller and cleaner campaign.