RE: Supression list / segment
This is how I did it:
Adding a Suppression Segment to a Customer Journey
If you are sending a customer journey to a segment, but want to exclude or suppress part of the segment, here’s how you can do that.
Create a Marketing List and include the members of the segment you want to suppress.
Create a Segment using the Static marketing lists members template and specify which Marketing List to include in the Marketing List > Is query.
Save the Segment and then make it Live.
Create a Customer Journey or modify one you already started. I’m using the Simple Email Journey template.
First, set the initial audience by clicking Set audience and choose the Segment you want to send the email to.
Then click + Add condition
Change Or to And
Change Inclusion to Exclusion
In the field below Exclusion search for the suppression segment you created in step 2.
The audience tile will reflect your conditions.
Then proceed to setup the rest of the journey by choosing the email and then the date and time to send the email in the General tab.