Segmenting your list simply means dividing it into sub groups such as people who opened, people who didn’t open, people who clicked, etc.
To create a list of segmented contacts:
Click Contacts and then Segmentation
Now you can choose the parameters for your segment.
Step 1: Choose a list to segment
Step 2: Choose if the contacts must match ANY or ALL of the conditions you specify.
Step 3: Select to segment by including or excluding contacts that you can specify from a wide variety of conditions in the drop down list. For example, you could include people who opened any of your email messages within the last 3 months but exclude those people who were sent a specific email campaign. You also have an option to create a custom field.
Step 4: Save your segment to a new list or save to an existing list. You can also save this search query to use it at a different time.
Step 5: When ready, click Create.