The Not like operator is used to select all those contacts for which the relevant attribute does not at least partially match the value entered in the condition input field. This means that the operator implicitly uses wildcards to match the input field with the relevant attribute values in the database.
Setting the Email condition to Not like, with ‘gmail’ as the input field value, selects all those contacts whose email address does not include ‘gmail’ anywhere in the relevant string.
The Not like operator applies to string data types.
See Input field types for more about each input field.